CATH Classification

Domain Context

CATH Clusters

Superfamily Amidase signature (AS) domain
Functional Family Glutamyl-tRNA(Gln) amidotransferase subunit A, mitochondrial

Enzyme Information
Glutaminyl-tRNA synthase (glutamine-hydrolyzing).
based on mapping to UniProt Q03557
ATP + L-glutamyl-tRNA(Gln) + L-glutamine = ADP + phosphate + L-glutaminyl-tRNA(Gln) + L-glutamate.
-!- In systems lacking discernible glutamine--tRNA ligase (EC, glutaminyl-tRNA(Gln) is formed by a two-enzyme system. -!- In the first step, a nondiscriminating ligase (EC 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 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

UniProtKB Entries (1)

Saccharomyces cerevisiae S288C
Glutamyl-tRNA(Gln) amidotransferase subunit B, mitochondrial

PDB Structure

External Links
Primary Citation
Crystal structure of Saccharomyces cerevisiae mitochondrial GatFAB reveals a novel subunit assembly in tRNA-dependent amidotransferases
Araiso, Y., Huot, J.L., Sekiguchi, T., Frechin, M., Fischer, F., Enkler, L., Senger, B., Ishitani, R., Becker, H.D., Nureki, O.
Nucleic Acids Res.