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tRNA aminoacylation by arginyl‐tRNA synthetase: induced conformations during substrates binding
Author(s) -
Delagoutte Bénédicte,
Moras Dino,
Cavarelli Jean
Publication year - 2000
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/19.21.5599
Subject(s) - aminoacylation , transfer rna , biology , ternary complex , biochemistry , aminoacyl trna synthetase , binding site , translation (biology) , enzyme , t arm , rna , messenger rna , gene
The 2.2 Å crystal structure of a ternary complex formed by yeast arginyl‐tRNA synthetase and its cognate tRNA Arg in the presence of the L ‐arginine substrate highlights new atomic features used for specific substrate recognition. This first example of an active complex formed by a class Ia aminoacyl‐tRNA synthetase and its natural cognate tRNA illustrates additional strategies used for specific tRNA selection. The enzyme specifically recognizes the D‐loop and the anticodon of the tRNA, and the mutually induced fit produces a conformation of the anticodon loop never seen before. Moreover, the anticodon binding triggers conformational changes in the catalytic center of the protein. The comparison with the 2.9 Å structure of a binary complex formed by yeast arginyl‐tRNA synthetase and tRNA Arg reveals that L ‐arginine binding controls the correct positioning of the CCA end of the tRNA Arg . Important structural changes induced by substrate binding are observed in the enzyme. Several key residues of the active site play multiple roles in the catalytic pathway and thus highlight the structural dynamics of the aminoacylation reaction.