Publications
2003
Caillet J, Nogueira T, Masquida B, Winter F, Graffe M, Dock-Bregeon A C, Torres-Larios A, Sankaranarayanan R, Westhof E, Ehresmann B, Ehresmann C, Romby P, Springer M
The modular structure of Escherichia coli threonyl-tRNA synthetase as both an enzyme and a regulator of gene expression Journal Article
In: Mol Microbiol, vol. 47, no. 4, pp. 961-974, 2003, ISBN: 12581352, (0950-382x Journal Article).
Abstract | Links | BibTeX | Tags: Amino Acyl/chemistry/metabolism Ribosomes/metabolism Support, Bacterial Genes, Bacterial Macromolecular Systems Models, Bacterial/chemistry/metabolism RNA, Binding Sites Binding, Competitive Escherichia coli/*enzymology/*genetics Evolution, Messenger/metabolism RNA, Molecular Gene Expression Regulation, Molecular Molecular Mimicry Molecular Structure Mutation Operator Regions (Genetics) Protein Structure, Non-U.S. Gov't Threonine-tRNA Ligase/*chemistry/genetics/*metabolism, ROMBY, Tertiary Protein Subunits RNA, Transfer, Unité ARN, WESTHOF
@article{,
title = {The modular structure of Escherichia coli threonyl-tRNA synthetase as both an enzyme and a regulator of gene expression},
author = {J Caillet and T Nogueira and B Masquida and F Winter and M Graffe and A C Dock-Bregeon and A Torres-Larios and R Sankaranarayanan and E Westhof and B Ehresmann and C Ehresmann and P Romby and M Springer},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12581352},
isbn = {12581352},
year = {2003},
date = {2003-01-01},
journal = {Mol Microbiol},
volume = {47},
number = {4},
pages = {961-974},
abstract = {In addition to its role in tRNA aminoacylation, Escherichia coli threonyl-tRNA synthetase is a regulatory protein which binds a site, called the operator, located in the leader of its own mRNA and inhibits translational initiation by competing with ribosome binding. This work shows that the two essential steps of regulation, operator recognition and inhibition of ribosome binding, are performed by different domains of the protein. The catalytic and the C-terminal domain of the protein are involved in binding the two anticodon arm-like structures in the operator whereas the N-terminal domain of the enzyme is responsible for the competition with the ribosome. This is the first demonstration of a modular structure for a translational repressor and is reminiscent of that of transcriptional regulators. The mimicry between the operator and tRNA, suspected on the basis of previous experiments, is further supported by the fact that identical regions of the synthetase recognize both the operator and the tRNA anticodon arm. Based on these results, and recent structural data, we have constructed a computer-derived molecular model for the operator-threonyl-tRNA synthetase complex, which sheds light on several essential aspects of the regulatory mechanism.},
note = {0950-382x
Journal Article},
keywords = {Amino Acyl/chemistry/metabolism Ribosomes/metabolism Support, Bacterial Genes, Bacterial Macromolecular Systems Models, Bacterial/chemistry/metabolism RNA, Binding Sites Binding, Competitive Escherichia coli/*enzymology/*genetics Evolution, Messenger/metabolism RNA, Molecular Gene Expression Regulation, Molecular Molecular Mimicry Molecular Structure Mutation Operator Regions (Genetics) Protein Structure, Non-U.S. Gov't Threonine-tRNA Ligase/*chemistry/genetics/*metabolism, ROMBY, Tertiary Protein Subunits RNA, Transfer, Unité ARN, WESTHOF},
pubstate = {published},
tppubtype = {article}
}
2000
Cura V, Moras D, Kern D
In: Eur J Biochem, vol. 267, no. 2, pp. 379-393, 2000, ISBN: 10632708, (0014-2956 Journal Article).
Abstract | Links | BibTeX | Tags: Amino Acid Motifs Amino Acid Sequence Bacterial Proteins/*genetics/*metabolism Base Sequence Cloning, Bacterial Molecular Sequence Data Phylogeny Regulatory Sequences, Molecular Enzyme Stability Escherichia coli/enzymology/genetics Evolution, Molecular Gene Expression Regulation, Non-U.S. Gov't Thermus thermophilus/*enzymology Threonine-tRNA Ligase/*genetics/*metabolism Zinc/metabolism, Nucleic Acid Sequence Analysis Support, Unité ARN
@article{,
title = {Sequence analysis and modular organization of threonyl-tRNA synthetase from Thermus thermophilus and its interrelation with threonyl-tRNA synthetases of other origins},
author = {V Cura and D Moras and D Kern},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=10632708},
isbn = {10632708},
year = {2000},
date = {2000-01-01},
journal = {Eur J Biochem},
volume = {267},
number = {2},
pages = {379-393},
abstract = {The gene encoding threonyl-tRNA synthetase (Thr-tRNA synthetase) from the extreme thermophilic eubacterium Thermus thermophilus HB8 has been cloned and sequenced. The ORF encodes a polypeptide chain of 659 amino acids (Mr 75 550) that shares strong similarities with other Thr-tRNA synthetases. Comparative analysis with the three-dimensional structure of other subclass IIa synthetases shows it to be organized into four structural modules: two N-terminal modules specific to Thr-tRNA synthetases, a catalytic core and a C-terminal anticodon-binding module. Comparison with the three-dimensional structure of Escherichia coli Thr-tRNA synthetase in complex with tRNAThr enabled identification of the residues involved in substrate binding and catalytic activity. Analysis by atomic absorption spectrometry of the enzyme overexpressed in E. coli revealed the presence in each monomer of one tightly bound zinc atom, which is essential for activity. Despite strong similarites in modular organization, Thr-tRNA synthetases diverge from other subclass IIa synthetases on the basis of their N-terminal extensions. The eubacterial and eukaryotic enzymes possess a large extension folded into two structural domains, N1 and N2, that are not significantly similar to the shorter extension of the archaebacterial enzymes. Investigation of a truncated Thr-tRNA synthetase demonstrated that domain N1 is not essential for tRNA charging. Thr-tRNA synthetase from T. thermophilus is of the eubacterial type, in contrast to other synthetases from this organism, which exhibit archaebacterial characteristics. Alignments show conservation of part of domain N2 in the C-terminal moiety of Ala-tRNA synthetases. Analysis of the nucleotide sequence upstream from the ORF showed the absence of both any anticodon-like stem-loop structure and a loop containing sequences complementary to the anticodon and the CCA end of tRNAThr. This means that the expression of Thr-tRNA synthetase in T. thermophilus is not regulated by the translational and trancriptional mechanisms described for E. coli thrS and Bacillus subtilis thrS and thrZ. Here we discuss our results in the context of evolution of the threonylation systems and of the position of T. thermophilus in the phylogenic tree.},
note = {0014-2956
Journal Article},
keywords = {Amino Acid Motifs Amino Acid Sequence Bacterial Proteins/*genetics/*metabolism Base Sequence Cloning, Bacterial Molecular Sequence Data Phylogeny Regulatory Sequences, Molecular Enzyme Stability Escherichia coli/enzymology/genetics Evolution, Molecular Gene Expression Regulation, Non-U.S. Gov't Thermus thermophilus/*enzymology Threonine-tRNA Ligase/*genetics/*metabolism Zinc/metabolism, Nucleic Acid Sequence Analysis Support, Unité ARN},
pubstate = {published},
tppubtype = {article}
}