Characterization of the human mitochondrial methionyl-tRNA synthetase.

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Spencer AC, Heck A, Takeuchi N, Watanabe K, Spremulli LL

Characterization of the human mitochondrial methionyl-tRNA synthetase.

Biochemistry. 2004 Aug 3;43(30):9743-54.

PubMed ID

15274629 [ View in PubMed

]

Abstract

Human mitochondrial methionyl-tRNA synthetase (human mtMetRS) has been identified from the human EST database. The cDNA encodes a 593 amino acid protein with an 18 amino acid mitochondrial import signal sequence. Sequence analysis indicates that this protein contains the consensus motifs characteristic of a class I aminoacyl-tRNA synthetase but lacks the Zn(2+) binding motif and C-terminal dimerization region found in MetRSs from various organisms. The mature form of human mtMetRS has been cloned and expressed in Escherichia coli. Gel filtration experiments indicate that this protein functions as a monomer with an apparent molecular mass of 67 kDa. The kinetic parameters for activation of methionine have been determined for the purified enzyme. The K(M) and k(cat) for aminoacylation of E. coli initiator tRNA(f)(Met) are reported. The kinetics of aminoacylation of an in vitro transcript of human mitochondrial tRNA(Met) (mtRNA(Met)) have been determined. To address the effects of the modification of mtRNA on recognition of the mitochondrial tRNA by human mtMetRS, the kinetics of aminoacylation of native bovine mtRNA(Met) and of an in vitro transcript of the bovine mtRNA(Met) have also been investigated.

DrugBank Data that Cites this Article

Drug Enzymes

Drug	Enzyme	Kind	Organism	Pharmacological Action	Actions
Methionine	Methionine--tRNA ligase, mitochondrial	Protein	Humans	Unknown	Substrate	Details

Polypeptides

Name	UniProt ID
Methionine--tRNA ligase, mitochondrial	Q96GW9	Details