2g5h
From Proteopedia
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Structure of tRNA-Dependent Amidotransferase GatCAB
Overview
The formation of glutaminyl transfer RNA (Gln-tRNA(Gln)) differs among the, three domains of life. Most bacteria employ an indirect pathway to produce, Gln-tRNA(Gln) by a heterotrimeric glutamine amidotransferase CAB (GatCAB), that acts on the misacylated Glu-tRNA(Gln). Here, we describe a series of, crystal structures of intact GatCAB from Staphylococcus aureus in the apo, form and in the complexes with glutamine, asparagine, Mn2+, and adenosine, triphosphate analog. Two identified catalytic centers for the glutaminase, and transamidase reactions are markedly distant but connected by a, hydrophilic ammonia channel 30 A in length. Further, we show that the, first U-A base pair in the acceptor stem and the D loop of tRNA(Gln) serve, as identity elements essential for discrimination by GatCAB and propose a, complete model for the overall concerted reactions to synthesize, Gln-tRNA(Gln).
About this Structure
2G5H is a Protein complex structure of sequences from Staphylococcus aureus with MG as ligand. Full crystallographic information is available from OCA.
Reference
Ammonia channel couples glutaminase with transamidase reactions in GatCAB., Nakamura A, Yao M, Chimnaronk S, Sakai N, Tanaka I, Science. 2006 Jun 30;312(5782):1954-8. PMID:16809541
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