| methionine—tRNA ligase | |
| Ec Number: | 6.1.1.10 |
| Cas Number: | 9033-22-1 |
| Go Code: | 0004825 |
| Width: | 270 |
In enzymology, a methionine—tRNA ligase is an enzyme that catalyzes the chemical reaction
ATP + L-methionine + tRNAMet
\rightleftharpoons
The 3 substrates of this enzyme are ATP, L-methionine, and tRNA(Met), whereas its 3 products are AMP, diphosphate, and L-methionyl-tRNA(Met).
This enzyme belongs to the family of ligases, to be specific those forming carbon-oxygen bonds in aminoacyl-tRNA and related compounds. The systematic name of this enzyme class is L-methionine:tRNAMet ligase (AMP-forming). Other names in common use include methionyl-tRNA synthetase, methionyl-transfer ribonucleic acid synthetase, methionyl-transfer ribonucleate synthetase, methionyl-transfer RNA synthetase, methionine translase, and MetRS. This enzyme participates in 3 metabolic pathways: methionine metabolism, selenoamino acid metabolism, and aminoacyl-trna biosynthesis.
During oxidative stress, methionine—tRNA ligase might be phosphorylated, which results in promiscuity of this enzyme, where it aminoacylates methionine to various non-Met tRNAs. This in turn leads to substitution of amino acids in proteins with methionine, which helps relieve oxidative stress in the cell.[1]
As of late 2007, 21 structures have been solved for this class of enzymes, with PDB accession codes,,,,,,,,,,,,,,,,,,,, and .