1bs2
From Proteopedia
YEAST ARGINYL-TRNA SYNTHETASE
Overview
The crystal structure of arginyl-tRNA synthetase (ArgRS) from Saccharomyces cerevisiae, a class I aminoacyl-tRNA synthetase (aaRS), with L-arginine bound to the active site has been solved at 2.75 A resolution and refined to a crystallographic R-factor of 19.7%. ArgRS is composed predominantly of alpha-helices and can be divided into five domains, including the class I-specific active site. The N-terminal domain shows striking similarity to some completely unrelated proteins and defines a module which should participate in specific tRNA recognition. The C-terminal domain, which is the putative anticodon-binding module, displays an all-alpha-helix fold highly similar to that of Escherichia coli methionyl-tRNA synthetase. While ArgRS requires tRNAArg for the first step of the aminoacylation reaction, the results show that its presence is not a prerequisite for L-arginine binding. All H-bond-forming capability of L-arginine is used by the protein for the specific recognition. The guanidinium group forms two salt bridge interactions with two acidic residues, and one H-bond with a tyrosine residue; these three residues are strictly conserved in all ArgRS sequences. This tyrosine is also conserved in other class I aaRS active sites but plays several functional roles. The ArgRS structure allows the definition of a new framework for sequence alignments and subclass definition in class I aaRSs.
About this Structure
1BS2 is a Single protein structure of sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
Reference
L-arginine recognition by yeast arginyl-tRNA synthetase., Cavarelli J, Delagoutte B, Eriani G, Gangloff J, Moras D, EMBO J. 1998 Sep 15;17(18):5438-48. PMID:9736621 Page seeded by OCA on Fri May 2 11:53:15 2008
