| 别名 |
AdT, AsnRS, Asp-AdT, Asp-tRNAAsn amidotransferase, Asp/Glu-Adt, asparaginyl-transfer RNA synthetase, Asparaginyl-tRNA synthetase, aspartyl-tRNAAsn amidotransferase, GatCAB, glutamine-dependent Asp-tRNAAsn/Glu-tRNAGln amidotransferase, NRS, tRNA-dependent amidotransferase |
| Comments |
This reaction forms part of a two-reaction system for producing asparaginyl-tRNA in?Deinococcus radiodurans?and other organisms lacking a specific enzyme for asparagine synthesis. In the first step, a non-discriminating ligase (EC?6.1.1.23, aspartate¡ªtRNAAsn?ligase) mischarges tRNAAsn?with aspartate, leading to the formation of aspartyl-tRNAAsn. The aspartyl-tRNAAsn?is not used in protein synthesis until the present enzyme converts it into asparaginyl-tRNAAsn?(aspartyl-tRNAAsp?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. Bacterial GatCAB complexes also has the activity of EC?6.3.5.7?(glutaminyl-tRNA synthase [glutamine-hydrolysing]). |
