Fender A, Sissler M, Florentz C, Giege R
Functional idiosyncrasies of tRNA isoacceptors in cognate and noncognate aminoacylation systems Journal Article
In: Biochimie, vol. 86, no. 1, pp. 21-29, 2004, ISBN: 14987797, (0300-9084 Journal Article).
Abstract | Links | BibTeX | Tags: Amino Acyl/genetics/*metabolism Saccharomyces cerevisiae Substrate Specificity/genetics/physiology Support, Chemical Molecular Sequence Data Mutation Nucleic Acid Conformation Protein Binding/physiology RNA, FLORENTZ, GIEGE FLORENTZ Amino Acid Activation/physiology Amino Acyl-tRNA Ligases/*metabolism Anticodon Bacterial Proteins/metabolism Base Sequence Cloning, Molecular Computer Simulation Escherichia coli Models, Non-U.S. Gov't Thermus thermophilus, SISSLER, Transfer, Transfer/genetics/*metabolism RNA, Unité ARN
@article{,
title = {Functional idiosyncrasies of tRNA isoacceptors in cognate and noncognate aminoacylation systems},
author = {A Fender and M Sissler and C Florentz and R Giege},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14987797},
isbn = {14987797},
year = {2004},
date = {2004-01-01},
journal = {Biochimie},
volume = {86},
number = {1},
pages = {21-29},
abstract = {The specificity of transfer RNA aminoacylation by cognate aminoacyl-tRNA synthetase is a crucial step for synthesis of functional proteins. It is established that the aminoacylation identity of a single tRNA or of a family of tRNA isoacceptors is linked to the presence of positive signals (determinants) allowing recognition by cognate synthetases and negative signals (antideterminants) leading to rejection by the noncognate ones. The completion of identity sets was generally tested by transplantation of the corresponding nucleotides into one or several host tRNAs which acquire as a consequence the new aminoacylation specificities. Such transplantation experiments were also useful to detect peculiar structural refinements required for optimal expression of a given aminoacylation identity set within a host tRNA. This study explores expression of the defined yeast aspartate identity set into different tRNA scaffolds of a same specificity, namely the four yeast tRNA(Arg) isoacceptors. The goal was to investigate whether expression of the new identity is similar due to the unique specificity of the host tRNAs or whether it is differently expressed due to their peculiar sequences and structural features. In vitro transcribed native tRNA(Arg) isoacceptors and variants bearing the aspartate identity elements were prepared and their aminoacylation properties established. The four wild-type isoacceptors are active in arginylation with catalytic efficiencies in a 20-fold range and are inactive in aspartylation. While transplanted tRNA(1)(Arg) and tRNA(4)(Arg) are converted into highly efficient substrates for yeast aspartyl-tRNA synthetase, transplanted tRNA(2)(Arg) and tRNA(3)(Arg) remain poorly aspartylated. Search for antideterminants in these two tRNAs reveals idiosyncratic features. Conversion of the single base-pair C6-G67 into G6-C67, the pair present in tRNA(Asp), allows full expression of the aspartate identity in the transplanted tRNA(2)(Arg), but not in tRNA(3)(Arg). It is concluded that the different isoacceptor tRNAs protect themselves from misaminoacylation by idiosyncratic pathways of antidetermination.},
note = {0300-9084
Journal Article},
keywords = {Amino Acyl/genetics/*metabolism Saccharomyces cerevisiae Substrate Specificity/genetics/physiology Support, Chemical Molecular Sequence Data Mutation Nucleic Acid Conformation Protein Binding/physiology RNA, FLORENTZ, GIEGE FLORENTZ Amino Acid Activation/physiology Amino Acyl-tRNA Ligases/*metabolism Anticodon Bacterial Proteins/metabolism Base Sequence Cloning, Molecular Computer Simulation Escherichia coli Models, Non-U.S. Gov't Thermus thermophilus, SISSLER, Transfer, Transfer/genetics/*metabolism RNA, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Giege R, Florentz C, Kern D, Gangloff J, Eriani G, Moras D
Aspartate identity of transfer RNAs Journal Article
In: Biochimie, vol. 78, no. 7, pp. 605-623, 1996, ISBN: 8955904, (0300-9084 Journal Article Review Review, Tutorial).
Abstract | Links | BibTeX | Tags: Asp/*chemistry Saccharomyces cerevisiae Structure-Activity Relationship Support, Aspartate-tRNA Ligase/chemistry/metabolism Aspartic Acid/analysis Base Sequence Escherichia coli Models, ERIANI, FLORENTZ, Molecular Molecular Sequence Data Nucleic Acid Conformation RNA, Non-U.S. Gov't Thermus thermophilus, Transfer, Unité ARN
@article{,
title = {Aspartate identity of transfer RNAs},
author = {R Giege and C Florentz and D Kern and J Gangloff and G Eriani and D Moras},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=8955904},
isbn = {8955904},
year = {1996},
date = {1996-01-01},
journal = {Biochimie},
volume = {78},
number = {7},
pages = {605-623},
abstract = {Structure/function relationships accounting for specific tRNA charging by class II aspartyl-tRNA synthetases from Saccharomyces cerevisiae, Escherichia coli and Thermus thermophilus are reviewed. Effects directly linked to tRNA features are emphasized and aspects about synthetase contribution in expression of tRNA(Asp) identity are also covered. Major identity nucleotides conferring aspartate specificity to yeast, E coli and T thermophilus tRNAs comprise G34, U35, C36, C38 and G73, a set of nucleotides conserved in tRNA(Asp) molecules of other biological origin. Aspartate specificity can be enhanced by negative discrimination preventing, eg mischarging of native yeast tRNA(Asp by yeast arginyl-tRNA synthetase. In the yeast system crystallography shows that identity nucleotides are in contact with identity amino acids located in the catalytic and anticodon binding domains of the synthetase. Specificity of RNA/protein interaction involves a conformational change of the tRNA that optimizes the H-bonding potential of the identity signals on both partners of the complex. Mutation of identity nucleotides leads to decreased aspartylation efficiencies accompanied by a loss of specific H-bonds and an altered adaptation of tRNA on the synthetase. Species-specific characteristics of aspartate systems are the number, location and nature of minor identity signals. These features and the structural variations in aspartate tRNAs and synthetases are correlated with mechanistic differences in the aminoacylation reactions catalyzed by the various aspartyl-tRNA synthetases. The reality of the aspartate identity set is verified by its functional expression in a variety of RNA frameworks. Inversely a number of identities can be expressed within a tRNA(Asp) framework. From this emerged the concept of the RNA structural frameworks underlying expression of identities which is illustrated with data obtained with engineered tRNAs. Efficient aspartylation of minihelices is explained by the primordial role of G73. From this and other considerations it is suggested that aspartate identity appeared early in the history of tRNA aminoacylation systems.},
note = {0300-9084
Journal Article
Review
Review, Tutorial},
keywords = {Asp/*chemistry Saccharomyces cerevisiae Structure-Activity Relationship Support, Aspartate-tRNA Ligase/chemistry/metabolism Aspartic Acid/analysis Base Sequence Escherichia coli Models, ERIANI, FLORENTZ, Molecular Molecular Sequence Data Nucleic Acid Conformation RNA, Non-U.S. Gov't Thermus thermophilus, Transfer, Unité ARN},
pubstate = {published},
tppubtype = {article}
}