1obc
From Proteopedia
LEUCYL-TRNA SYNTHETASE FROM THERMUS THERMOPHILUS COMPLEXED WITH A POST-TRANSFER EDITING SUBSTRATE ANALOGUE
Overview
The aminoacyl-tRNA synthetases link tRNAs with their cognate amino acid. In some cases, their fidelity relies on hydrolytic editing that destroys incorrectly activated amino acids or mischarged tRNAs. We present structures of leucyl-tRNA synthetase complexed with analogs of the distinct pre- and posttransfer editing substrates. The editing active site binds the two different substrates using a single amino acid discriminatory pocket while preserving the same mode of adenine recognition. This suggests a similar mechanism of hydrolysis for both editing substrates that depends on a key, completely conserved aspartic acid, which interacts with the alpha-amino group of the noncognate amino acid and positions both substrates for hydrolysis. Our results demonstrate the economy by which a single active site accommodates two distinct substrates in a proofreading process critical to the fidelity of protein synthesis.
About this Structure
1OBC is a Single protein structure of sequence from Thermus thermophilus. Full crystallographic information is available from OCA.
Reference
Structural and mechanistic basis of pre- and posttransfer editing by leucyl-tRNA synthetase., Lincecum TL Jr, Tukalo M, Yaremchuk A, Mursinna RS, Williams AM, Sproat BS, Van Den Eynde W, Link A, Van Calenbergh S, Grotli M, Martinis SA, Cusack S, Mol Cell. 2003 Apr;11(4):951-63. PMID:12718881 Page seeded by OCA on Sat May 3 03:37:40 2008
