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2023
Arrivé Mathilde, Bruggeman Mathieu, Skaltsogiannis Vasileios, Coudray Léna, Quan Yi-Fat, Schelcher Cédric, Cognat Valérie, Hammann Philippe, Chicher Johana, Wolff Philippe, Gobert Anthony, Giegé Philippe
A tRNA-modifying enzyme facilitates RNase P activity in Arabidopsis nuclei Journal Article
In: Nat Plants, 2023, ISSN: 2055-0278.
Abstract | Links | BibTeX | Tags: ARN-MS, PPSE, Unité ARN
@article{pmid37945696,
title = {A tRNA-modifying enzyme facilitates RNase P activity in Arabidopsis nuclei},
author = {Mathilde Arrivé and Mathieu Bruggeman and Vasileios Skaltsogiannis and Léna Coudray and Yi-Fat Quan and Cédric Schelcher and Valérie Cognat and Philippe Hammann and Johana Chicher and Philippe Wolff and Anthony Gobert and Philippe Giegé},
doi = {10.1038/s41477-023-01564-0},
issn = {2055-0278},
year = {2023},
date = {2023-11-01},
urldate = {2023-11-01},
journal = {Nat Plants},
abstract = {RNase P is the essential activity that performs the 5' maturation of transfer RNA (tRNA) precursors. Beyond the ancestral form of RNase P containing a ribozyme, protein-only RNase P enzymes termed PRORP were identified in eukaryotes. In human mitochondria, PRORP forms a complex with two protein partners to become functional. In plants, although PRORP enzymes are active alone, we investigate their interaction network to identify potential tRNA maturation complexes. Here we investigate functional interactions involving the Arabidopsis nuclear RNase P PRORP2. We show, using an immuno-affinity strategy, that PRORP2 occurs in a complex with the tRNA methyl transferases TRM1A and TRM1B in vivo. Beyond RNase P, these enzymes can also interact with RNase Z. We show that TRM1A/TRM1B localize in the nucleus and find that their double knockout mutation results in a severe macroscopic phenotype. Using a combination of immuno-detections, mass spectrometry and a transcriptome-wide tRNA sequencing approach, we observe that TRM1A/TRM1B are responsible for the mG26 modification of 70% of cytosolic tRNAs in vivo. We use the transcriptome wide tRNAseq approach as well as RNA blot hybridizations to show that RNase P activity is impaired in TRM1A/TRM1B mutants for specific tRNAs, in particular, tRNAs containing a mG modification at position 26 that are strongly downregulated in TRM1A/TRM1B mutants. Altogether, results indicate that the mG-adding enzymes TRM1A/TRM1B functionally cooperate with nuclear RNase P in vivo for the early steps of cytosolic tRNA biogenesis.},
keywords = {ARN-MS, PPSE, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
RNase P is the essential activity that performs the 5' maturation of transfer RNA (tRNA) precursors. Beyond the ancestral form of RNase P containing a ribozyme, protein-only RNase P enzymes termed PRORP were identified in eukaryotes. In human mitochondria, PRORP forms a complex with two protein partners to become functional. In plants, although PRORP enzymes are active alone, we investigate their interaction network to identify potential tRNA maturation complexes. Here we investigate functional interactions involving the Arabidopsis nuclear RNase P PRORP2. We show, using an immuno-affinity strategy, that PRORP2 occurs in a complex with the tRNA methyl transferases TRM1A and TRM1B in vivo. Beyond RNase P, these enzymes can also interact with RNase Z. We show that TRM1A/TRM1B localize in the nucleus and find that their double knockout mutation results in a severe macroscopic phenotype. Using a combination of immuno-detections, mass spectrometry and a transcriptome-wide tRNA sequencing approach, we observe that TRM1A/TRM1B are responsible for the mG26 modification of 70% of cytosolic tRNAs in vivo. We use the transcriptome wide tRNAseq approach as well as RNA blot hybridizations to show that RNase P activity is impaired in TRM1A/TRM1B mutants for specific tRNAs, in particular, tRNAs containing a mG modification at position 26 that are strongly downregulated in TRM1A/TRM1B mutants. Altogether, results indicate that the mG-adding enzymes TRM1A/TRM1B functionally cooperate with nuclear RNase P in vivo for the early steps of cytosolic tRNA biogenesis.
Vindry Caroline, Guillin Olivia, Wolff Philippe, Marie Paul, Mortreux Franck, Mangeot Philippe E, Ohlmann Théophile, Chavatte Laurent
A homozygous mutation in the human selenocysteine tRNA gene impairs UGA recoding activity and selenoproteome regulation by selenium Journal Article
In: Nucleic Acids Res, 2023, ISSN: 1362-4962.
Abstract | Links | BibTeX | Tags: ARN-MS, Unité ARN
@article{pmid37254812,
title = {A homozygous mutation in the human selenocysteine tRNA gene impairs UGA recoding activity and selenoproteome regulation by selenium},
author = {Caroline Vindry and Olivia Guillin and Philippe Wolff and Paul Marie and Franck Mortreux and Philippe E Mangeot and Théophile Ohlmann and Laurent Chavatte},
doi = {10.1093/nar/gkad482},
issn = {1362-4962},
year = {2023},
date = {2023-05-01},
urldate = {2023-05-01},
journal = {Nucleic Acids Res},
abstract = {The selenocysteine (Sec) tRNA (tRNA[Ser]Sec) governs Sec insertion into selenoproteins by the recoding of a UGA codon, typically used as a stop codon. A homozygous point mutation (C65G) in the human tRNA[Ser]Sec acceptor arm has been reported by two independent groups and was associated with symptoms such as thyroid dysfunction and low blood selenium levels; however, the extent of altered selenoprotein synthesis resulting from this mutation has yet to be comprehensively investigated. In this study, we used CRISPR/Cas9 technology to engineer homozygous and heterozygous mutant human cells, which we then compared with the parental cell lines. This C65G mutation affected many aspects of tRNA[Ser]Sec integrity and activity. Firstly, the expression level of tRNA[Ser]Sec was significantly reduced due to an altered recruitment of RNA polymerase III at the promoter. Secondly, selenoprotein expression was strongly altered, but, more surprisingly, it was no longer sensitive to selenium supplementation. Mass spectrometry analyses revealed a tRNA isoform with unmodified wobble nucleotide U34 in mutant cells that correlated with reduced UGA recoding activities. Overall, this study demonstrates the pleiotropic effect of a single C65G mutation on both tRNA phenotype and selenoproteome expression.},
keywords = {ARN-MS, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
The selenocysteine (Sec) tRNA (tRNA[Ser]Sec) governs Sec insertion into selenoproteins by the recoding of a UGA codon, typically used as a stop codon. A homozygous point mutation (C65G) in the human tRNA[Ser]Sec acceptor arm has been reported by two independent groups and was associated with symptoms such as thyroid dysfunction and low blood selenium levels; however, the extent of altered selenoprotein synthesis resulting from this mutation has yet to be comprehensively investigated. In this study, we used CRISPR/Cas9 technology to engineer homozygous and heterozygous mutant human cells, which we then compared with the parental cell lines. This C65G mutation affected many aspects of tRNA[Ser]Sec integrity and activity. Firstly, the expression level of tRNA[Ser]Sec was significantly reduced due to an altered recruitment of RNA polymerase III at the promoter. Secondly, selenoprotein expression was strongly altered, but, more surprisingly, it was no longer sensitive to selenium supplementation. Mass spectrometry analyses revealed a tRNA isoform with unmodified wobble nucleotide U34 in mutant cells that correlated with reduced UGA recoding activities. Overall, this study demonstrates the pleiotropic effect of a single C65G mutation on both tRNA phenotype and selenoproteome expression.
Gosset-Erard Clarisse, Didierjean Mévie, Pansanel Jérome, Lechner Antony, Wolff Philippe, Kuhn Lauriane, Aubriet Frédéric, Leize-Wagner Emmanuelle, Chaimbault Patrick, François Yannis-Nicolas
In: Anal Chem, vol. 95, iss. 2, pp. 1608-1617, 2023, ISSN: 1520-6882.
Abstract | Links | BibTeX | Tags: ARN-MS, PPSE, Unité ARN
@article{pmid36598775,
title = {Nucleos'ID: A New Search Engine Enabling the Untargeted Identification of RNA Post-transcriptional Modifications from Tandem Mass Spectrometry Analyses of Nucleosides},
author = {Clarisse Gosset-Erard and Mévie Didierjean and Jérome Pansanel and Antony Lechner and Philippe Wolff and Lauriane Kuhn and Frédéric Aubriet and Emmanuelle Leize-Wagner and Patrick Chaimbault and Yannis-Nicolas François},
doi = {10.1021/acs.analchem.2c04722},
issn = {1520-6882},
year = {2023},
date = {2023-01-01},
urldate = {2023-01-01},
journal = {Anal Chem},
volume = {95},
issue = {2},
pages = {1608-1617},
abstract = {As RNA post-transcriptional modifications are of growing interest, several methods were developed for their characterization. One of them established for their identification, at the nucleosidic level, is the hyphenation of separation methods, such as liquid chromatography or capillary electrophoresis, to tandem mass spectrometry. However, to our knowledge, no software is yet available for the untargeted identification of RNA post-transcriptional modifications from MS/MS data-dependent acquisitions. Thus, very long and tedious manual data interpretations are required. To meet the need of easier and faster data interpretation, a new user-friendly search engine, called Nucleos'ID, was developed for CE-MS/MS and LC-MS/MS users. Performances of this new software were evaluated on CE-MS/MS data from nucleoside analyses of already well-described transfer RNA and total tRNA extract. All samples showed great true positive, true negative, and false discovery rates considering the database size containing all modified and unmodified nucleosides referenced in the literature. The true positive and true negative rates obtained were above 0.94, while the false discovery rates were between 0.09 and 0.17. To increase the level of sample complexity, untargeted identification of several RNA modifications from 70S ribosome was achieved by the Nucleos'ID search following CE-MS/MS analysis.},
keywords = {ARN-MS, PPSE, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
As RNA post-transcriptional modifications are of growing interest, several methods were developed for their characterization. One of them established for their identification, at the nucleosidic level, is the hyphenation of separation methods, such as liquid chromatography or capillary electrophoresis, to tandem mass spectrometry. However, to our knowledge, no software is yet available for the untargeted identification of RNA post-transcriptional modifications from MS/MS data-dependent acquisitions. Thus, very long and tedious manual data interpretations are required. To meet the need of easier and faster data interpretation, a new user-friendly search engine, called Nucleos'ID, was developed for CE-MS/MS and LC-MS/MS users. Performances of this new software were evaluated on CE-MS/MS data from nucleoside analyses of already well-described transfer RNA and total tRNA extract. All samples showed great true positive, true negative, and false discovery rates considering the database size containing all modified and unmodified nucleosides referenced in the literature. The true positive and true negative rates obtained were above 0.94, while the false discovery rates were between 0.09 and 0.17. To increase the level of sample complexity, untargeted identification of several RNA modifications from 70S ribosome was achieved by the Nucleos'ID search following CE-MS/MS analysis.
2022
Roovers Martine L, Labar Geoffray, Wolff Philippe, Feller Andre, Elder Dany Van, Soin Romuald, Gueydan Cyril, Kruys Veronique, Droogmans Louis
In: RNA, vol. 28, iss. 9, pp. 1185-1196, 2022, ISSN: 1469-9001.
Abstract | Links | BibTeX | Tags: ARN-MS, ENNIFAR, Unité ARN
@article{pmid35710145b,
title = {The Bacillus subtilis open reading frame ysgA encodes the SPOUT methyltransferase RlmP forming 2'-O-methylguanosine at position 2553 in the A-loop of 23S rRNA},
author = {Martine L Roovers and Geoffray Labar and Philippe Wolff and Andre Feller and Dany Van Elder and Romuald Soin and Cyril Gueydan and Veronique Kruys and Louis Droogmans},
doi = {10.1261/rna.079131.122},
issn = {1469-9001},
year = {2022},
date = {2022-06-01},
urldate = {2022-06-01},
journal = {RNA},
volume = {28},
issue = {9},
pages = {1185-1196},
abstract = {A previous bioinformatic analysis predicted that the ysgA open reading frame of Bacillus subtilis encodes an RNA methyltransferase of the SPOUT superfamily. Here we show that YsgA is the 2'-O-methyltransferase that targets position G2553 (Escherichia coli numbering) of the A-loop of 23S rRNA. This was shown by a combination of biochemical and mass spectrometry approaches using both rRNA extracted from B. subtilis wild-type or ΔysgA cells and in vitro synthesized rRNA. When the target G2553 is mutated, YsgA is able to methylate the ribose of adenosine. However it cannot methylate cytidine nor uridine. The enzyme modifies free 23S rRNA but not the fully assembled ribosome nor the 50S subunit, suggesting that the modification occurs early during ribosome biogenesis. Nevertheless ribosome subunits assembly is unaffected in a B. subtilis ΔysgA mutant strain. The crystal structure of the recombinant YsgA protein, combined with mutagenesis data, outlined in this article highlights a typical SPOUT fold preceded by an L7Ae/L30 (eL8/eL30 in a new nomenclature) N-terminal domain.},
keywords = {ARN-MS, ENNIFAR, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
A previous bioinformatic analysis predicted that the ysgA open reading frame of Bacillus subtilis encodes an RNA methyltransferase of the SPOUT superfamily. Here we show that YsgA is the 2'-O-methyltransferase that targets position G2553 (Escherichia coli numbering) of the A-loop of 23S rRNA. This was shown by a combination of biochemical and mass spectrometry approaches using both rRNA extracted from B. subtilis wild-type or ΔysgA cells and in vitro synthesized rRNA. When the target G2553 is mutated, YsgA is able to methylate the ribose of adenosine. However it cannot methylate cytidine nor uridine. The enzyme modifies free 23S rRNA but not the fully assembled ribosome nor the 50S subunit, suggesting that the modification occurs early during ribosome biogenesis. Nevertheless ribosome subunits assembly is unaffected in a B. subtilis ΔysgA mutant strain. The crystal structure of the recombinant YsgA protein, combined with mutagenesis data, outlined in this article highlights a typical SPOUT fold preceded by an L7Ae/L30 (eL8/eL30 in a new nomenclature) N-terminal domain.
2021
Andre C, Veillard F, Wolff P, Lobstein A M, Compain G, Monsarrat C, Reichhart J M, Burnouf D Y, Guichard G, Wagner J E
Antibacterial activity of a dual peptide targeting the Escherichia coli sliding clamp and the ribosome Journal Article
In: RSC Chem Biol, vol. 2, no. 4, pp. 1296, 2021, ISBN: 34459830, (2633-0679 (Electronic) 2633-0679 (Linking) Published Erratum).
Abstract | Links | BibTeX | Tags: ARN-MS, ENNIFAR, reichhart, Unité ARN
@article{,
title = {Antibacterial activity of a dual peptide targeting the Escherichia coli sliding clamp and the ribosome},
author = {C Andre and F Veillard and P Wolff and A M Lobstein and G Compain and C Monsarrat and J M Reichhart and D Y Burnouf and G Guichard and J E Wagner},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=34459830},
doi = {10.1039/d1cb90020j},
isbn = {34459830},
year = {2021},
date = {2021-01-01},
journal = {RSC Chem Biol},
volume = {2},
number = {4},
pages = {1296},
abstract = {[This corrects the article DOI: 10.1039/D0CB00060D.].},
note = {2633-0679 (Electronic)
2633-0679 (Linking)
Published Erratum},
keywords = {ARN-MS, ENNIFAR, reichhart, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
[This corrects the article DOI: 10.1039/D0CB00060D.].
Cela M, Theobald-Dietrich A, Rudinger-Thirion J, Wolff P, Geslain R, Frugier M
Identification of host tRNAs preferentially recognized by the Plasmodium surface protein tRip Journal Article
In: Nucleic Acids Res, 2021, ISBN: 34530443, (1362-4962 (Electronic) 0305-1048 (Linking) Journal Article).
Abstract | Links | BibTeX | Tags: ARN-MS, FRUGIER, Unité ARN
@article{,
title = {Identification of host tRNAs preferentially recognized by the Plasmodium surface protein tRip},
author = {M Cela and A Theobald-Dietrich and J Rudinger-Thirion and P Wolff and R Geslain and M Frugier},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=34530443},
doi = {10.1093/nar/gkab769},
isbn = {34530443},
year = {2021},
date = {2021-01-01},
journal = {Nucleic Acids Res},
abstract = {Malaria is a life-threatening and devastating parasitic disease. Our previous work showed that parasite development requires the import of exogenous transfer RNAs (tRNAs), which represents a novel and unique form of host-pathogen interaction, as well as a potentially druggable target. This import is mediated by tRip (tRNA import protein), a membrane protein located on the parasite surface. tRip displays an extracellular domain homologous to the well-characterized OB-fold tRNA-binding domain, a structural motif known to indiscriminately interact with tRNAs. We used MIST (Microarray Identification of Shifted tRNAs), a previously established in vitro approach, to systematically assess the specificity of complexes between native Homo sapiens tRNAs and recombinant Plasmodium falciparum tRip. We demonstrate that tRip unexpectedly binds to host tRNAs with a wide range of affinities, suggesting that only a small subset of human tRNAs is preferentially imported into the parasite. In particular, we show with in vitro transcribed constructs that tRip does not bind specific tRNAs solely based on their primary sequence, hinting that post-transcriptional modifications modulate the formation of our host/parasite molecular complex. Finally, we discuss the potential utilization of the most efficient tRip ligands for the translation of the parasite's genetic information.},
note = {1362-4962 (Electronic)
0305-1048 (Linking)
Journal Article},
keywords = {ARN-MS, FRUGIER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Malaria is a life-threatening and devastating parasitic disease. Our previous work showed that parasite development requires the import of exogenous transfer RNAs (tRNAs), which represents a novel and unique form of host-pathogen interaction, as well as a potentially druggable target. This import is mediated by tRip (tRNA import protein), a membrane protein located on the parasite surface. tRip displays an extracellular domain homologous to the well-characterized OB-fold tRNA-binding domain, a structural motif known to indiscriminately interact with tRNAs. We used MIST (Microarray Identification of Shifted tRNAs), a previously established in vitro approach, to systematically assess the specificity of complexes between native Homo sapiens tRNAs and recombinant Plasmodium falciparum tRip. We demonstrate that tRip unexpectedly binds to host tRNAs with a wide range of affinities, suggesting that only a small subset of human tRNAs is preferentially imported into the parasite. In particular, we show with in vitro transcribed constructs that tRip does not bind specific tRNAs solely based on their primary sequence, hinting that post-transcriptional modifications modulate the formation of our host/parasite molecular complex. Finally, we discuss the potential utilization of the most efficient tRip ligands for the translation of the parasite's genetic information.
Monsarrat C., Compain G., Andre C., Engilberge S., Martiel I., Olieric V., Wolff P., Brillet K., Landolfo M., da Veiga C. Silva, Wagner J., Guichard G., Burnouf D. Y.
Iterative Structure-Based Optimization of Short Peptides Targeting the Bacterial Sliding Clamp Journal Article
In: J Med Chem, 2021, ISBN: 34806883, (1520-4804 (Electronic) 0022-2623 (Linking) Journal Article).
Abstract | Links | BibTeX | Tags: ARN-MS, ENNIFAR, Unité ARN
@article{nokey,
title = {Iterative Structure-Based Optimization of Short Peptides Targeting the Bacterial Sliding Clamp},
author = {C. Monsarrat and G. Compain and C. Andre and S. Engilberge and I. Martiel and V. Olieric and P. Wolff and K. Brillet and M. Landolfo and C. Silva da Veiga and J. Wagner and G. Guichard and D. Y. Burnouf},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=34806883},
doi = {10.1021/acs.jmedchem.1c00918},
isbn = {34806883},
year = {2021},
date = {2021-01-01},
journal = {J Med Chem},
abstract = {The bacterial DNA sliding clamp (SC), or replication processivity factor, is a promising target for the development of novel antibiotics. We report a structure-activity relationship study of a new series of peptides interacting within the Escherichia coli SC ((Ec)SC) binding pocket. Various modifications were explored including N-alkylation of the peptide bonds, extension of the N-terminal moiety, and introduction of hydrophobic and constrained residues at the C-terminus. In each category, single modifications were identified that increased affinity to (Ec)SC. A combination of such modifications yielded in several cases to a substantially increased affinity compared to the parent peptides with Kd in the range of 30-80 nM. X-ray structure analysis of 11 peptide/(Ec)SC co-crystals revealed new interactions at the peptide-protein interface (i.e., stacking interactions, hydrogen bonds, and hydrophobic contacts) that can account for the improved binding. Several compounds among the best binders were also found to be more effective in inhibiting SC-dependent DNA synthesis.},
note = {1520-4804 (Electronic)
0022-2623 (Linking)
Journal Article},
keywords = {ARN-MS, ENNIFAR, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
The bacterial DNA sliding clamp (SC), or replication processivity factor, is a promising target for the development of novel antibiotics. We report a structure-activity relationship study of a new series of peptides interacting within the Escherichia coli SC ((Ec)SC) binding pocket. Various modifications were explored including N-alkylation of the peptide bonds, extension of the N-terminal moiety, and introduction of hydrophobic and constrained residues at the C-terminus. In each category, single modifications were identified that increased affinity to (Ec)SC. A combination of such modifications yielded in several cases to a substantially increased affinity compared to the parent peptides with Kd in the range of 30-80 nM. X-ray structure analysis of 11 peptide/(Ec)SC co-crystals revealed new interactions at the peptide-protein interface (i.e., stacking interactions, hydrogen bonds, and hydrophobic contacts) that can account for the improved binding. Several compounds among the best binders were also found to be more effective in inhibiting SC-dependent DNA synthesis.
Ramos-Morales E, Bayam E, Del-Pozo-Rodriguez J, Salinas-Giege T, Marek M, Tilly P, Wolff P, Troesch E, Ennifar E, Drouard L, Godin J D, Romier C
The structure of the mouse ADAT2/ADAT3 complex reveals the molecular basis for mammalian tRNA wobble adenosine-to-inosine deamination Journal Article
In: Nucleic Acids Res, vol. 49, no. 11, pp. 6529-6548, 2021, ISBN: 34057470, (1362-4962 (Electronic) 0305-1048 (Linking) Journal Article).
Abstract | Links | BibTeX | Tags: ARN-MS, ENNIFAR, Unité ARN
@article{,
title = {The structure of the mouse ADAT2/ADAT3 complex reveals the molecular basis for mammalian tRNA wobble adenosine-to-inosine deamination},
author = {E Ramos-Morales and E Bayam and J Del-Pozo-Rodriguez and T Salinas-Giege and M Marek and P Tilly and P Wolff and E Troesch and E Ennifar and L Drouard and J D Godin and C Romier},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=34057470},
doi = {10.1093/nar/gkab436},
isbn = {34057470},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Nucleic Acids Res},
volume = {49},
number = {11},
pages = {6529-6548},
abstract = {Post-transcriptional modification of tRNA wobble adenosine into inosine is crucial for decoding multiple mRNA codons by a single tRNA. The eukaryotic wobble adenosine-to-inosine modification is catalysed by the ADAT (ADAT2/ADAT3) complex that modifies up to eight tRNAs, requiring a full tRNA for activity. Yet, ADAT catalytic mechanism and its implication in neurodevelopmental disorders remain poorly understood. Here, we have characterized mouse ADAT and provide the molecular basis for tRNAs deamination by ADAT2 as well as ADAT3 inactivation by loss of catalytic and tRNA-binding determinants. We show that tRNA binding and deamination can vary depending on the cognate tRNA but absolutely rely on the eukaryote-specific ADAT3 N-terminal domain. This domain can rotate with respect to the ADAT catalytic domain to present and position the tRNA anticodon-stem-loop correctly in ADAT2 active site. A founder mutation in the ADAT3 N-terminal domain, which causes intellectual disability, does not affect tRNA binding despite the structural changes it induces but most likely hinders optimal presentation of the tRNA anticodon-stem-loop to ADAT2.},
note = {1362-4962 (Electronic)
0305-1048 (Linking)
Journal Article},
keywords = {ARN-MS, ENNIFAR, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Post-transcriptional modification of tRNA wobble adenosine into inosine is crucial for decoding multiple mRNA codons by a single tRNA. The eukaryotic wobble adenosine-to-inosine modification is catalysed by the ADAT (ADAT2/ADAT3) complex that modifies up to eight tRNAs, requiring a full tRNA for activity. Yet, ADAT catalytic mechanism and its implication in neurodevelopmental disorders remain poorly understood. Here, we have characterized mouse ADAT and provide the molecular basis for tRNAs deamination by ADAT2 as well as ADAT3 inactivation by loss of catalytic and tRNA-binding determinants. We show that tRNA binding and deamination can vary depending on the cognate tRNA but absolutely rely on the eukaryote-specific ADAT3 N-terminal domain. This domain can rotate with respect to the ADAT catalytic domain to present and position the tRNA anticodon-stem-loop correctly in ADAT2 active site. A founder mutation in the ADAT3 N-terminal domain, which causes intellectual disability, does not affect tRNA binding despite the structural changes it induces but most likely hinders optimal presentation of the tRNA anticodon-stem-loop to ADAT2.
2020
Wolff P, Villette C, Zumsteg J, Heintz D, Antoine L, Chane-Woon-Ming B, Droogmans L, Grosjean H, Westhof E
Comparative patterns of modified nucleotides in individual tRNA species from a mesophilic and two thermophilic archaea Journal Article
In: RNA, vol. 26, no. 12, pp. 1957-1975, 2020.
Abstract | Links | BibTeX | Tags: (hyper)thermophiles Archaea mass spectrometry modifications tRNA, ARN-MS, ENNIFAR, Unité ARN, WESTHOF
@article{,
title = {Comparative patterns of modified nucleotides in individual tRNA species from a mesophilic and two thermophilic archaea},
author = {P Wolff and C Villette and J Zumsteg and D Heintz and L Antoine and B Chane-Woon-Ming and L Droogmans and H Grosjean and E Westhof},
url = {https://pubmed.ncbi.nlm.nih.gov/32994183/},
doi = {10.1261/rna.077537.120},
year = {2020},
date = {2020-09-29},
journal = {RNA},
volume = {26},
number = {12},
pages = {1957-1975},
abstract = {To improve and complete our knowledge of archaeal tRNA modification patterns, we have identified and compared the modification pattern (type and location) in tRNAs of three very different archaeal species, Methanococcus maripaludis (a mesophilic methanogen), Pyrococcus furiosus (a hyperthermophile thermococcale) and Sulfolobus acidocaldarius (an acidophilic thermophilic sulfolobale). Most abundant isoacceptor tRNAs (79 in total) for each of the 20 amino acids were isolated by two-dimensional gel electrophoresis followed by in-gel RNase digestions. The resulting oligonucleotide fragments were separated by nanoLC and their nucleotide content analyzed by mass spectrometry (MS/MS). Analysis of total modified nucleosides obtained from complete digestion of bulk tRNAs was also performed. Distinct base- and/or ribose-methylations, cytidine acetylations and thiolated pyrimidines were identified, some at new positions in tRNAs. Novel, some tentatively identified, modifications were also found. The least diversified modification landscape is observed in the mesophilic Methanococcus maripaludis and the most complex one in Sulfolobus acidocaldarius. Notable observations are the frequent occurrence of ac4C nucleotides in thermophilic archaeal tRNAs, the presence of m7G at positions 1 and 10 in Pyrococcus furiosus tRNAs, and the use of wyosine derivatives at position 37 of tRNAs especially those decoding U1- and C1-starting codons. These results complete those already obtained by others with sets of archaeal tRNAs from Methanocaldococcus jannaschii and Haloferax volcanii.},
keywords = {(hyper)thermophiles Archaea mass spectrometry modifications tRNA, ARN-MS, ENNIFAR, Unité ARN, WESTHOF},
pubstate = {published},
tppubtype = {article}
}
To improve and complete our knowledge of archaeal tRNA modification patterns, we have identified and compared the modification pattern (type and location) in tRNAs of three very different archaeal species, Methanococcus maripaludis (a mesophilic methanogen), Pyrococcus furiosus (a hyperthermophile thermococcale) and Sulfolobus acidocaldarius (an acidophilic thermophilic sulfolobale). Most abundant isoacceptor tRNAs (79 in total) for each of the 20 amino acids were isolated by two-dimensional gel electrophoresis followed by in-gel RNase digestions. The resulting oligonucleotide fragments were separated by nanoLC and their nucleotide content analyzed by mass spectrometry (MS/MS). Analysis of total modified nucleosides obtained from complete digestion of bulk tRNAs was also performed. Distinct base- and/or ribose-methylations, cytidine acetylations and thiolated pyrimidines were identified, some at new positions in tRNAs. Novel, some tentatively identified, modifications were also found. The least diversified modification landscape is observed in the mesophilic Methanococcus maripaludis and the most complex one in Sulfolobus acidocaldarius. Notable observations are the frequent occurrence of ac4C nucleotides in thermophilic archaeal tRNAs, the presence of m7G at positions 1 and 10 in Pyrococcus furiosus tRNAs, and the use of wyosine derivatives at position 37 of tRNAs especially those decoding U1- and C1-starting codons. These results complete those already obtained by others with sets of archaeal tRNAs from Methanocaldococcus jannaschii and Haloferax volcanii.
Wolff P, Ennifar E
Native Electrospray Ionization Mass Spectrometry of RNA-Ligand Complexes Book Chapter
In: Arluison, V; Wien, F (Ed.): RNA Spectroscopy: Methods and Protocols, vol. 2113, pp. 111-118, Springer Protocols, Humana Press, New York, NY, 2020, ISBN: 32006311.
Abstract | Links | BibTeX | Tags: ARN-MS, ENNIFAR, Native mass spectrometry RNA, Unité ARN
@inbook{,
title = {Native Electrospray Ionization Mass Spectrometry of RNA-Ligand Complexes},
author = {P Wolff and E Ennifar},
editor = {V Arluison and F Wien},
url = {https://pubmed.ncbi.nlm.nih.gov/32006311},
doi = {10.1007/978-1-0716-0278-2_9},
isbn = {32006311},
year = {2020},
date = {2020-01-01},
booktitle = {RNA Spectroscopy: Methods and Protocols},
volume = {2113},
pages = {111-118},
publisher = {Springer Protocols, Humana Press},
address = {New York, NY},
series = {Methods in Molecular Biology},
abstract = {Native electrospray ionization mass spectrometry (native ESI-MS) is a powerful tool to investigate non-covalent biomolecular interactions. It has been widely used to study protein complexes, but only few examples are described for the analysis of complexes involving RNA-RNA interactions. Here, we provide a detailed protocol for native ESI-MS analysis of RNA complexes. As an example, we present the analysis of the HIV-1 genomic RNA dimerization initiation site (DIS) extended duplex dimer bound to the aminoglycoside antibiotic lividomycin.},
keywords = {ARN-MS, ENNIFAR, Native mass spectrometry RNA, Unité ARN},
pubstate = {published},
tppubtype = {inbook}
}
Native electrospray ionization mass spectrometry (native ESI-MS) is a powerful tool to investigate non-covalent biomolecular interactions. It has been widely used to study protein complexes, but only few examples are described for the analysis of complexes involving RNA-RNA interactions. Here, we provide a detailed protocol for native ESI-MS analysis of RNA complexes. As an example, we present the analysis of the HIV-1 genomic RNA dimerization initiation site (DIS) extended duplex dimer bound to the aminoglycoside antibiotic lividomycin.
Lechner A, Wolff P, Leize-Wagner E, François Y N
Characterization of Post-Transcriptional RNA Modifications by Sheathless Capillary Electrophoresis-High Resolution Mass Spectrometry Journal Article
In: Anal Chem, vol. 92, no. 10, pp. 7363-7370, 2020, ISBN: 32343557.
Abstract | Links | BibTeX | Tags: ARN-MS, ENNIFAR, Unité ARN
@article{,
title = {Characterization of Post-Transcriptional RNA Modifications by Sheathless Capillary Electrophoresis-High Resolution Mass Spectrometry},
author = {A Lechner and P Wolff and E Leize-Wagner and Y N François},
url = {https://www.ncbi.nlm.nih.gov/pubmed/32343557?dopt=Abstract},
doi = {10.1021/acs.analchem.0c01345},
isbn = {32343557},
year = {2020},
date = {2020-01-01},
journal = {Anal Chem},
volume = {92},
number = {10},
pages = {7363-7370},
abstract = {Over the past decade there has been a growing interest in RNA modification analysis. High performance liquid chromatography-tandem mass spectrometry coupling (HPLC-MS/MS) is classically used to characterize post-transcriptional modifications of ribonucleic acids (RNAs). Here we propose a novel and simple workflow based on capillary zone electrophoresis-tandem mass spectrometry (CE-MS/MS), in positive mode, to characterize RNA modifications at nucleoside and oligonucleotide levels. By first totally digesting the purified RNA, prior to CE-MS/MS analysis, we were able to identify the nucleoside modifications. Then, using a bottom-up approach, sequencing of the RNAs and mapping of the modifications were performed. Sequence coverages from 68% to 97% were obtained for four tRNAs. Furthermore, unambiguous identification and mapping of several modifications were achieved.},
keywords = {ARN-MS, ENNIFAR, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Over the past decade there has been a growing interest in RNA modification analysis. High performance liquid chromatography-tandem mass spectrometry coupling (HPLC-MS/MS) is classically used to characterize post-transcriptional modifications of ribonucleic acids (RNAs). Here we propose a novel and simple workflow based on capillary zone electrophoresis-tandem mass spectrometry (CE-MS/MS), in positive mode, to characterize RNA modifications at nucleoside and oligonucleotide levels. By first totally digesting the purified RNA, prior to CE-MS/MS analysis, we were able to identify the nucleoside modifications. Then, using a bottom-up approach, sequencing of the RNAs and mapping of the modifications were performed. Sequence coverages from 68% to 97% were obtained for four tRNAs. Furthermore, unambiguous identification and mapping of several modifications were achieved.
Antoine L, Wolff P
Mapping of Posttranscriptional tRNA Modifications by Two-Dimensional Gel Electrophoresis Mass Spectrometry Book Chapter
In: Arluison, V; Wien, F (Ed.): RNA Spectroscopy: Methods and Protocols, vol. 2113, pp. 101-110, Springer Protocols, Humana Press, New York, NY, 2020, ISBN: 32006310.
Abstract | Links | BibTeX | Tags: 2D Gel isolation Nano-LC-MS/MS Posttranscriptional tRNA modifications, ARN-MS, ENNIFAR, ROMBY, Unité ARN
@inbook{,
title = {Mapping of Posttranscriptional tRNA Modifications by Two-Dimensional Gel Electrophoresis Mass Spectrometry},
author = {L Antoine and P Wolff},
editor = {V Arluison and F Wien},
url = {https://pubmed.ncbi.nlm.nih.gov/32006310},
doi = {10.1007/978-1-0716-0278-2_8},
isbn = {32006310},
year = {2020},
date = {2020-01-01},
booktitle = {RNA Spectroscopy: Methods and Protocols},
volume = {2113},
pages = {101-110},
publisher = {Springer Protocols, Humana Press},
address = {New York, NY},
series = {Methods in Molecular Biology},
abstract = {RNA modification mapping by mass spectrometry (MS) is based on the use of specific ribonucleases (RNases) that generate short oligonucleotide digestion products which are further separated by nano-liquid chromatography and analyzed by MS and MS/MS. Recent developments in MS instrumentation allow the possibility to deeply explore posttranscriptional modifications. Notably, development of nano-liquid chromatography and nano-electrospray drastically increases the detection sensitivity and allows the identification and sequencing of RNA digested fragments separated and extracted from two-dimensional polyacrylamide gels, as long as the mapping and characterization of ribonucleotide modifications.},
keywords = {2D Gel isolation Nano-LC-MS/MS Posttranscriptional tRNA modifications, ARN-MS, ENNIFAR, ROMBY, Unité ARN},
pubstate = {published},
tppubtype = {inbook}
}
RNA modification mapping by mass spectrometry (MS) is based on the use of specific ribonucleases (RNases) that generate short oligonucleotide digestion products which are further separated by nano-liquid chromatography and analyzed by MS and MS/MS. Recent developments in MS instrumentation allow the possibility to deeply explore posttranscriptional modifications. Notably, development of nano-liquid chromatography and nano-electrospray drastically increases the detection sensitivity and allows the identification and sequencing of RNA digested fragments separated and extracted from two-dimensional polyacrylamide gels, as long as the mapping and characterization of ribonucleotide modifications.
2019
Antoine L, Wolff P, Westhof E, Romby P, Marzi S
Mapping post-transcriptional modifications in Staphylococcus aureus tRNAs by nanoLC/MSMS Journal Article
In: Biochimie, vol. 164, pp. 60-69, 2019, ISBN: 31295507.
Abstract | Links | BibTeX | Tags: 2D gel isolation Staphylococcus aureus nanoLC/MSMS post-transcriptional tRNA modifications, ARN-MS, ENNIFAR, ROMBY, Unité ARN, WESTHOF
@article{,
title = {Mapping post-transcriptional modifications in Staphylococcus aureus tRNAs by nanoLC/MSMS},
author = {L Antoine and P Wolff and E Westhof and P Romby and S Marzi},
url = {https://www.ncbi.nlm.nih.gov/pubmed/31295507?dopt=Abstract},
doi = {10.1016/j.biochi.2019.07.003},
isbn = {31295507},
year = {2019},
date = {2019-01-01},
journal = {Biochimie},
volume = {164},
pages = {60-69},
abstract = {RNA modifications are involved in numerous biological processes. These modifications are constitutive or modulated in response to adaptive processes and can impact RNA base pairing formation, protein recognition, RNA structure and stability. tRNAs are the most abundantly modified RNA molecules. Analysis of the roles of their modifications in response to stress, environmental changes, and infections caused by pathogens, has fueled new research areas. Nevertheless, the detection of modified nucleotides in RNAs is still a challenging task. We present here a reliable method to identify and localize tRNA modifications, which was applied to the human pathogenic bacteria, Staphyloccocus aureus. The method is based on a separation of tRNA species on a two-dimensional polyacrylamide gel electrophoresis followed by nano liquid chromatography-mass spectrometry. We provided a list of modifications mapped on 25 out of the 40 tRNA species (one isoacceptor for each amino acid). This method can be easily used to monitor the dynamics of tRNA modifications in S. aureus in response to stress adaptation and during infection of the host, a relatively unexplored field.},
keywords = {2D gel isolation Staphylococcus aureus nanoLC/MSMS post-transcriptional tRNA modifications, ARN-MS, ENNIFAR, ROMBY, Unité ARN, WESTHOF},
pubstate = {published},
tppubtype = {article}
}
RNA modifications are involved in numerous biological processes. These modifications are constitutive or modulated in response to adaptive processes and can impact RNA base pairing formation, protein recognition, RNA structure and stability. tRNAs are the most abundantly modified RNA molecules. Analysis of the roles of their modifications in response to stress, environmental changes, and infections caused by pathogens, has fueled new research areas. Nevertheless, the detection of modified nucleotides in RNAs is still a challenging task. We present here a reliable method to identify and localize tRNA modifications, which was applied to the human pathogenic bacteria, Staphyloccocus aureus. The method is based on a separation of tRNA species on a two-dimensional polyacrylamide gel electrophoresis followed by nano liquid chromatography-mass spectrometry. We provided a list of modifications mapped on 25 out of the 40 tRNA species (one isoacceptor for each amino acid). This method can be easily used to monitor the dynamics of tRNA modifications in S. aureus in response to stress adaptation and during infection of the host, a relatively unexplored field.
André C, Martiel I, Wolff P, Landolfo M, Lorber B, da Veiga C Silva, Dejaegere A, Dumas P, Guichard G, Olieric V, Wagner J G, Burnouf D Y
Interaction of a Model Peptide on Gram Negative and Gram Positive Bacterial Sliding Clamps Journal Article
In: ACS Infect Dis, vol. 5, no. 6, pp. 1022-1034, 2019, ISBN: 30912430.
Abstract | Links | BibTeX | Tags: ARN-MS, ENNIFAR, FRUGIER, ITC ligand−target interaction new antibacterials development sliding clamp, Unité ARN
@article{,
title = {Interaction of a Model Peptide on Gram Negative and Gram Positive Bacterial Sliding Clamps},
author = {C André and I Martiel and P Wolff and M Landolfo and B Lorber and C Silva da Veiga and A Dejaegere and P Dumas and G Guichard and V Olieric and J G Wagner and D Y Burnouf},
url = {https://www.ncbi.nlm.nih.gov/pubmed/30912430?dopt=Abstract},
doi = {10.1021/acsinfecdis.9b00089},
isbn = {30912430},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
journal = {ACS Infect Dis},
volume = {5},
number = {6},
pages = {1022-1034},
abstract = {Bacterial sliding clamps control the access of DNA polymerases to the replication fork and are appealing targets for antibacterial drugs development. It is therefore essential to decipher the polymerase-clamp binding mode across various bacterial species. Here, two residues of the E. coli clamp binding pocket, EcS346 and EcM362, and their cognate residues in M. tuberculosis and B. subtilis clamps, were mutated. The effects of these mutations on the interaction of a model peptide with these variant clamps were evaluated by thermodynamic, molecular dynamics, X-rays crystallography and biochemical analyses. EcM362 and corresponding residues in Gram positive clamps occupy a strategic position where a mobile residue is essential for an efficient peptide interaction. EcS346 has a more subtle function that modulates the pocket folding dynamics, while the equivalent residue in B. subtilis is essential for polymerase activity and might therefore be a Gram positive specific molecular marker. Finally, the peptide binds through an induced-fit process to Gram negative and positive pockets but the complex stability varies according to a pocket specific network of interactions.},
keywords = {ARN-MS, ENNIFAR, FRUGIER, ITC ligand−target interaction new antibacterials development sliding clamp, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Bacterial sliding clamps control the access of DNA polymerases to the replication fork and are appealing targets for antibacterial drugs development. It is therefore essential to decipher the polymerase-clamp binding mode across various bacterial species. Here, two residues of the E. coli clamp binding pocket, EcS346 and EcM362, and their cognate residues in M. tuberculosis and B. subtilis clamps, were mutated. The effects of these mutations on the interaction of a model peptide with these variant clamps were evaluated by thermodynamic, molecular dynamics, X-rays crystallography and biochemical analyses. EcM362 and corresponding residues in Gram positive clamps occupy a strategic position where a mobile residue is essential for an efficient peptide interaction. EcS346 has a more subtle function that modulates the pocket folding dynamics, while the equivalent residue in B. subtilis is essential for polymerase activity and might therefore be a Gram positive specific molecular marker. Finally, the peptide binds through an induced-fit process to Gram negative and positive pockets but the complex stability varies according to a pocket specific network of interactions.
2018
Rozov A, Wolff P, Grosjean H, Yusupov M, Yusupova G, Westhof E
Tautomeric G*U pairs within the molecular ribosomal grip and fidelity of decoding in bacteria Journal Article
In: Nucleic Acids Res, vol. 46, no. 14, pp. 7425-7435, 2018, ISBN: 29931292.
Abstract | Links | BibTeX | Tags: ARN-MS, ENNIFAR, Unité ARN, WESTHOF
@article{,
title = {Tautomeric G*U pairs within the molecular ribosomal grip and fidelity of decoding in bacteria},
author = {A Rozov and P Wolff and H Grosjean and M Yusupov and G Yusupova and E Westhof},
url = {https://www.ncbi.nlm.nih.gov/pubmed/29931292?dopt=Abstract},
doi = {10.1093/nar/gky547},
isbn = {29931292},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
journal = {Nucleic Acids Res},
volume = {46},
number = {14},
pages = {7425-7435},
abstract = {We report new crystallographic structures of Thermus thermophilus ribosomes complexed with long mRNAs and native Escherichia coli tRNAs. They complete the full set of combinations of Watson-Crick GC and miscoding GU pairs at the first two positions of the codon-anticodon duplex in ribosome functional complexes. Within the tight decoding center, miscoding GU pairs occur, in all combinations, with a non-wobble geometry structurally indistinguishable from classical coding Watson-Crick pairs at the same first two positions. The contacts with the ribosomal grip surrounding the decoding center are all quasi-identical, except in the crowded environment of the amino group of a guanosine at the second position; in which case a G in the codons may be preferred. In vivo experimental data show that the translational errors due to miscoding by GU pairs at the first two positions are the most frequently encountered ones, especially at the second position and with a G on the codon. Such preferred miscodings involve a switch from an A-U to a GU pair in the tRNA/mRNA complex and very rarely from a G = C to a GU pair. It is concluded that the frequencies of such occurrences are only weakly affected by the codon/anticodon structures but depend mainly on the stability and lifetime of the complex, the modifications present in the anticodon loop, especially those at positions 34 and 37, in addition to the relative concentration of cognate/near-cognate tRNA species present in the cellular tRNA pool.},
keywords = {ARN-MS, ENNIFAR, Unité ARN, WESTHOF},
pubstate = {published},
tppubtype = {article}
}
We report new crystallographic structures of Thermus thermophilus ribosomes complexed with long mRNAs and native Escherichia coli tRNAs. They complete the full set of combinations of Watson-Crick GC and miscoding GU pairs at the first two positions of the codon-anticodon duplex in ribosome functional complexes. Within the tight decoding center, miscoding GU pairs occur, in all combinations, with a non-wobble geometry structurally indistinguishable from classical coding Watson-Crick pairs at the same first two positions. The contacts with the ribosomal grip surrounding the decoding center are all quasi-identical, except in the crowded environment of the amino group of a guanosine at the second position; in which case a G in the codons may be preferred. In vivo experimental data show that the translational errors due to miscoding by GU pairs at the first two positions are the most frequently encountered ones, especially at the second position and with a G on the codon. Such preferred miscodings involve a switch from an A-U to a GU pair in the tRNA/mRNA complex and very rarely from a G = C to a GU pair. It is concluded that the frequencies of such occurrences are only weakly affected by the codon/anticodon structures but depend mainly on the stability and lifetime of the complex, the modifications present in the anticodon loop, especially those at positions 34 and 37, in addition to the relative concentration of cognate/near-cognate tRNA species present in the cellular tRNA pool.
2017
Wolff P, Veiga C Da, Ennifar E, Bec G, Guichard G, Burnouf D, Dumas P
Native ESI Mass Spectrometry Can Help to Avoid Wrong Interpretations from Isothermal Titration Calorimetry in Difficult Situations. Journal Article
In: J Am Soc Mass Spectrom, vol. 28, no. 2, pp. 347-357, 2017, ISBN: 27957716.
Abstract | Links | BibTeX | Tags: ARN-MS, DNA-polymerase processivity rings ESI-MS ITC Kd determination, ENNIFAR, Unité ARN
@article{,
title = {Native ESI Mass Spectrometry Can Help to Avoid Wrong Interpretations from Isothermal Titration Calorimetry in Difficult Situations.},
author = {P Wolff and C Da Veiga and E Ennifar and G Bec and G Guichard and D Burnouf and P Dumas},
url = {https://www.ncbi.nlm.nih.gov/pubmed/27957716?dopt=Abstract},
doi = {10.1007/s13361-016-1534-6},
isbn = {27957716},
year = {2017},
date = {2017-01-01},
journal = {J Am Soc Mass Spectrom},
volume = {28},
number = {2},
pages = {347-357},
abstract = {We studied by native ESI-MS the binding of various DNA-polymerase-derived peptides onto DNA-polymerase processivity rings from Escherichia coli, Pseudomonas aeruginosa, and Mycobacterium tuberculosis. These homodimeric rings present two equivalent specific binding sites, which leads to successive formation during a titration experiment of singly- and doubly occupied rings. By using the ESI-MS free-ring spectrum as a ruler, we derived by robust linear regression the fractions of the different ring species at each step of a titration experiment. These results led to accurate Kd values (from 0.03 to 0.5 μM) along with the probability of peptide loss due to gas phase dissociation (GPD). We show that this good quality is due to the increased information content of a titration experiment with a homodimer. Isothermal titration calorimetry (ITC) led with the same binding model to Kd(ITC) values systematically higher than their ESI-MS counterparts and, often, to poor fit of the ITC curves. A processing with two competing modes of binding on the same site requiring determination of two (Kd, ΔH) pairs greatly improved the fits and yielded a second Kd(ITC) close to Kd(ESI-MS). The striking features are: (1) ITC detected a minor binding mode (~20%) of 'low-affinity' that did not appear with ESI-MS; (2) the simplest processing of ITC data with only one (Kd, ΔH) pair led wrongly to the Kd of the low-affinity binding mode but to the ΔH of the high-affinity binding mode. Analogous misleading results might well exist in published data based on ITC experiments. Graphical Abstract ᅟ.},
keywords = {ARN-MS, DNA-polymerase processivity rings ESI-MS ITC Kd determination, ENNIFAR, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
We studied by native ESI-MS the binding of various DNA-polymerase-derived peptides onto DNA-polymerase processivity rings from Escherichia coli, Pseudomonas aeruginosa, and Mycobacterium tuberculosis. These homodimeric rings present two equivalent specific binding sites, which leads to successive formation during a titration experiment of singly- and doubly occupied rings. By using the ESI-MS free-ring spectrum as a ruler, we derived by robust linear regression the fractions of the different ring species at each step of a titration experiment. These results led to accurate Kd values (from 0.03 to 0.5 μM) along with the probability of peptide loss due to gas phase dissociation (GPD). We show that this good quality is due to the increased information content of a titration experiment with a homodimer. Isothermal titration calorimetry (ITC) led with the same binding model to Kd(ITC) values systematically higher than their ESI-MS counterparts and, often, to poor fit of the ITC curves. A processing with two competing modes of binding on the same site requiring determination of two (Kd, ΔH) pairs greatly improved the fits and yielded a second Kd(ITC) close to Kd(ESI-MS). The striking features are: (1) ITC detected a minor binding mode (~20%) of 'low-affinity' that did not appear with ESI-MS; (2) the simplest processing of ITC data with only one (Kd, ΔH) pair led wrongly to the Kd of the low-affinity binding mode but to the ΔH of the high-affinity binding mode. Analogous misleading results might well exist in published data based on ITC experiments. Graphical Abstract ᅟ.