Member database | SUPERFAMILY |
SUPERFAMILY type | homologous superfamily |
Description Imported from IPR009008
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
[2, 1]. The CP1 domain as an isolated polypeptide hydrolyses its cognate mischarged tRNA
[3].
References Imported from IPR009008
1.Leucyl-tRNA synthetase editing domain functions as a molecular rheostat to control codon ambiguity in Mycoplasma pathogens. Li L, Palencia A, Lukk T, Li Z, Luthey-Schulten ZA, Cusack S, Martinis SA, Boniecki MT. Proc. Natl. Acad. Sci. U.S.A. 110, 3817-22, (2013). View articlePMID: 23431144
2.Structural basis for substrate recognition by the editing domain of isoleucyl-tRNA synthetase. Fukunaga R, Yokoyama S. J. Mol. Biol. 359, 901-12, (2006). View articlePMID: 16697013
3.Plasticity of recognition of the 3'-end of mischarged tRNA by class I aminoacyl-tRNA synthetases. Nordin BE, Schimmel P. J. Biol. Chem. 277, 20510-7, (2002). View articlePMID: 11923317