Homologous Superfamily

Valyl/Leucyl/Isoleucyl-tRNA synthetase, editing domain (IPR009008)

Short name: Val/Leu/Ile-tRNA-synth_edit

Description

Certain aminoacyl-tRNA synthetases prevent potential errors in protein synthesis through deacylation of mischarged tRNAs. The close homologues isoleucyl-tRNA synthetase (IleRS) and valyl-tRNA synthetase (ValRS) deacylate Val-tRNAIle and Thr-tRNAVal, respectively. These reactions strictly require the presence of the cognate tRNA. In the absence of tRNA, the enzymatically generated misactivated adenylates remain in the active site, sequestered from hydrolysis. Upon addition of cognate tRNA the misactivated amino acids are hydrolysed, regenerating the free tRNA and amino acid, while converting 1 equivalent of ATP to AMP. A prominent mechanism for editing misactivated amino acids is the rapid hydrolysis of transiently mischarged tRNA. This reaction is catalysed at a second active site on IleRS and ValRS. This site is located within a large insertion (termed CP1) into the canonical class I aminoacyl-tRNA synthetase active-site fold [PMID: 16697013, PMID: 23431144]. The CP1 domain as an isolated polypeptide hydrolyses its cognate mischarged tRNA [PMID: 11923317].

GO terms

Biological Process

GO:0006418 tRNA aminoacylation for protein translation

Molecular Function

GO:0002161 aminoacyl-tRNA editing activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
GENE3D
SUPERFAMILY