2G5H

Structure of tRNA-Dependent Amidotransferase GatCAB

Summary for 2G5H

• Entry DOI: 10.2210/pdb2g5h/pdb
• Related: 2DF4 2F2A 2G5I
• Descriptor: Glutamyl-tRNA(Gln) amidotransferase subunit A, Aspartyl/glutamyl-tRNA(Asn/Gln) amidotransferase subunit B, Aspartyl/glutamyl-tRNA(Asn/Gln) amidotransferase subunit C, ... (5 entities in total)
• Functional Keywords: multi protein complex, ligase
• Biological source: Staphylococcus aureus; More
• Total number of polymer chains: 3
• Total formula weight: 118957.08

Authors

Nakamura, A.,Yao, M.,Tanaka, I. (deposition date: 2006-02-23, release date: 2006-07-18, Last modification date: 2024-03-13)

Primary citation

Nakamura, A.,Yao, M.,Chimnaronk, S.,Sakai, N.,Tanaka, I.
Ammonia channel couples glutaminase with transamidase reactions in GatCAB
Science, 312:1954-1958, 2006

PubMed Abstract: 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).

PubMed: 16809541
DOI: 10.1126/science.1127156

Experimental method

X-RAY DIFFRACTION (2.5 Å)