| 别名 |
aa-tRNA amidotransferase, AdT, amidotransferase B, amidotransferase C, amidotransferase, glutamyl-transfer ribonucleate (glutamine-specific), aminoacyl-tRNA amidotransferase, BANKA_112750, gatA, GatB, GatCAB, GatCAB amidotransferase, GatDE, Gln4, GlnRS, Glu-AdT, Glu-amidotransferase, Glu-tRNAGln amidotransferase, Glu-tRNAGlnAT, GluAdT GatDE, GluRS, glutamyl-tRNA(Gln) amidotransferase, glutamyl-tRNAGln amidotransferase, nondiscriminating GluRS, PBANKA_071810, PF3D7_0416100, PF3D7_0628800, Qrsl1 |
| Comments |
In systems lacking discernible glutamine¡ªtRNA ligase (EC?6.1.1.18), glutaminyl-tRNAGln?is formed by a two-enzyme system. In the first step, a nondiscriminating ligase (EC?6.1.1.24, glutamate¡ªtRNAGln?ligase) mischarges tRNAGln?with glutamate, forming glutamyl-tRNAGln. The glutamyl-tRNAGln?is not used in protein synthesis until the present enzyme converts it into glutaminyl-tRNAGln?(glutamyl-tRNAGlu?is not a substrate for this enzyme). A glutaminase subunit (cf. EC?3.5.1.2, glutaminase) produces an ammonia molecule that is transferred by a 30 ? 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?(asparaginyl-tRNA synthase [glutamine-hydrolysing]). |
