HMM Summary Page: TIGR00398

Functionmethionine--tRNA ligase
Gene SymbolmetG
Trusted Cutoff336.35
Domain Trusted Cutoff336.35
Noise Cutoff216.40
Domain Noise Cutoff216.40
Isology Typeequivalog_domain
EC Number6.1.1.10
HMM Length530
Mainrole CategoryProtein synthesis
Subrole CategorytRNA aminoacylation
Gene Ontology TermGO:0004825: methionine-tRNA ligase activity molecular_function
GO:0005737: cytoplasm cellular_component
GO:0006431: methionyl-tRNA aminoacylation biological_process
AuthorHaft DH
Entry DateApr 20 1999 2:08PM
Last ModifiedJun 1 2014 4:07PM
CommentThe methionyl-tRNA synthetase (metG) is a class I amino acyl-tRNA ligase. This HMM appears to recognize the methionyl-tRNA synthetase of every species, including eukaryotic cytosolic and mitochondrial forms. The UPGMA difference tree calculated after search and alignment according to this HMM shows an unusual deep split between two families of MetG. One family contains forms from the Archaea, yeast cytosol, spirochetes, and E. coli, among others. The other family includes forms from yeast mitochondrion, Synechocystis sp., Bacillus subtilis, the Mycoplasmas, Aquifex aeolicus, and Helicobacter pylori. The E. coli enzyme is homodimeric, although monomeric forms can be prepared that are fully active. Activity of this enzyme in bacteria includes aminoacylation of fMet-tRNA with Met; subsequent formylation of the Met to fMet is catalyzed by a separate enzyme. Note that the protein from Aquifex aeolicus is split into an alpha (large) and beta (small) subunit; this model does not include the C-terminal region corresponding to the beta chain.
ReferencesDR PROSITE PDOC00161; Aminoacyl-transfer RNA synthetases class-I signature DR HAMAP; MF_01228; 38 of 38 RN [1] RM PMID:19015366 RT Inhibition of methionyl-tRNA synthetase by REP8839 and effects of resistance mutations on enzyme activity. RA Green LS, Bullard JM, Ribble W, Dean F, Ayers DF, Ochsner UA, Janjic N, Jarvis TC RL Antimicrob Agents Chemother. 2009 Jan;53(1):86-94. doi: 10.1128/AAC.00275-08.
Genome PropertyGenProp0258: tRNA aminoacylation (HMM)