2amc
From Proteopedia
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Crystal structure of Phenylalanyl-tRNA synthetase complexed with L-tyrosine
Overview
Aminoacyl-tRNA synthetases (aaRSs) exert control over the faithful, transfer of amino acids onto cognate tRNAs. Since chemical structures of, various amino acids closely resemble each other, it is difficult to, discriminate between them. Editing activity has been evolved by certain, aaRSs to resolve the problem. In this study, we determined the crystal, structures of complexes of T. thermophilus phenylalanyl-tRNA synthetase, (PheRS) with L-tyrosine, p-chloro-phenylalanine, and a nonhydrolyzable, tyrosyl-adenylate analog. The structures demonstrate plasticity of the, synthetic site capable of binding substrates larger than phenylalanine and, provide a structural basis for the proofreading mechanism. The editing, site is localized at the B3/B4 interface, 35 A from the synthetic site., Glubeta334 plays a crucial role in the specific recognition of the Tyr, moiety in the editing site. The tyrosyl-adenylate analog binds exclusively, in the synthetic site. Both structural data and tyrosine-dependent ATP, hydrolysis enhanced by tRNA(Phe) provide evidence for a preferential, posttransfer editing pathway in the phenylalanine-specific system.
About this Structure
2AMC is a Protein complex structure of sequences from Thermus thermophilus with MG, SO4 and TYR as ligands. Active as Phenylalanine--tRNA ligase, with EC number 6.1.1.20 Full crystallographic information is available from OCA.
Reference
Structural basis for discrimination of L-phenylalanine from L-tyrosine by phenylalanyl-tRNA synthetase., Kotik-Kogan O, Moor N, Tworowski D, Safro M, Structure. 2005 Dec;13(12):1799-807. PMID:16338408
Page seeded by OCA on Wed Nov 21 08:13:08 2007
