Methionine—tRNA ligase
In enzymology, a methionine—tRNA ligase (EC 6.1.1.10) is an enzyme that catalyzes the chemical reaction
- ATP + L-methionine + tRNAMet AMP + diphosphate + L-methionyl-tRNAMet
| methionine—tRNA ligase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Methionine--tRNA ligase monomer, Human | |||||||||
| Identifiers | |||||||||
| EC no. | 6.1.1.10 | ||||||||
| CAS no. | 9033-22-1 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
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.
Role in oxidative stress
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]
Structural studies
As of late 2007, 21 structures have been solved for this class of enzymes, with PDB accession codes 1A8H, 1F4L, 1MEA, 1MED, 1MKH, 1P7P, 1PFU, 1PFV, 1PFW, 1PFY, 1PG0, 1PG2, 1QQT, 1RQG, 1WOY, 2CSX, 2CT8, 2D54, 2D5B, 2DJV, and 2HSN.
References
- Aledo JC (October 2019). "Methionine in proteins: The Cinderella of the proteinogenic amino acids". Protein Science. 28 (10): 1785–1796. doi:10.1002/pro.3698. PMC 6739822. PMID 31359525.
Further reading
- Bergmann FH, Berg P, Dieckmann M (1961). "The enzymic synthesis of amino acyl derivatives of ribonucleic acid II. The preparation of leucyl-, valyl-, isoleucyl- and methionyl ribonucleic acid synthetases from Escherichia coli". J. Biol. Chem. 236: 1735–1740. doi:10.1016/S0021-9258(19)63294-1.
- Lee CP, Dyson MR, Mandal N, Varshney U, Bahramian B, RajBhandary UL (October 1992). "Striking effects of coupling mutations in the acceptor stem on recognition of tRNAs by Escherichia coli Met-tRNA synthetase and Met-tRNA transformylase". Proceedings of the National Academy of Sciences of the United States of America. 89 (19): 9262–9266. Bibcode:1992PNAS...89.9262L. doi:10.1073/pnas.89.19.9262. PMC 50106. PMID 1409632.