CATH Classification

Domain Context

CATH Clusters

Superfamily Amidase signature (AS) domain
Functional Family

Enzyme Information

6.3.5.7
Glutaminyl-tRNA synthase (glutamine-hydrolyzing).
based on mapping to UniProt O66610
ATP + L-glutamyl-tRNA(Gln) + L-glutamine = ADP + phosphate + L-glutaminyl-tRNA(Gln) + L-glutamate.
-!- In systems lacking discernible glutamine--tRNA ligase (EC 6.1.1.18), glutaminyl-tRNA(Gln) is formed by a two-enzyme system. -!- In the first step, a nondiscriminating ligase (EC 6.1.1.24) mischarges tRNA(Gln) with glutamate, forming glutamyl-tRNA(Gln). -!- The glutamyl-tRNA(Gln) is not used in protein synthesis until the present enzyme converts it into glutaminyl-tRNA(Gln) (glutamyl- tRNA(Glu) is not a substrate for this enzyme). -!- A glutaminase subunit (cf. EC 3.5.1.2) produces an ammonia molecule that is transferred by a 30 A tunnel to a synthase subunit, where it is ligated to the carboxy group that has been activated by phosphorylation. -!- Some bacterial GatCAB complexes also has the activity of EC 6.3.5.6.

UniProtKB Entries (1)

O66766
GATB_AQUAE
Aquifex aeolicus VF5
Aspartyl/glutamyl-tRNA(Asn/Gln) amidotransferase subunit B

PDB Structure

PDB 3H0L
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Insights into tRNA-Dependent Amidotransferase Evolution and Catalysis from the Structure of the Aquifex aeolicus Enzyme
Wu, J., Bu, W., Sheppard, K., Kitabatake, M., Kwon, S.T., Soll, D., Smith, J.L.
J.Mol.Biol.