2df4
Structure of tRNA-Dependent Amidotransferase GatCAB complexed with Mn2+
OverviewOverview
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 StructureAbout this Structure
2DF4 is a Protein complex structure of sequences from Staphylococcus aureus. Full crystallographic information is available from OCA.
ReferenceReference
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 Page seeded by OCA on Sun May 4 00:18:21 2008