methionine synthase


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me·thi·o·nine syn·thase

tetrahydropteroylglutamate methyltransferase; methionine-homocysteine methyltransferase; an enzyme that catalyzes the reaction of N5-methyltetrahydrofolate with l-homocysteine to form tetrahydrofolate and l-methionine; a cobalamin-requiring enzyme; a deficiency of this enzyme results in an accumulation of l-homocysteine and neurological abnormalities.

methionine synthase

(1) 5-Methyltetrahydrofolate-homocysteine S-methyltransferase, EC 2.1.1.13.
(2) O-Acetylhomoserine (thiol)-lyase, EC 4.2.99.10.
References in periodicals archive ?
12] is a required cofactor for methionine synthase, while folic acid is a required cofactor for 5, 10-methylenetetrahydrofolate reductase.
The metabolism of the amino acid homocysteine consists of a vitamin B6-dependent trans-sulfuration pathway involving the enzyme Cystathionine [beta]-Synthase (CBS) and a folate- and vitamin B12-dependent remethylation pathway involving the enzymes Methylene Tetrahydrofolate Reductase (MTHFR) and methionine synthase deficiencies.
Methionine synthase (MS) is a key component of the methionine cycle in one-carbon metabolism and it catalyzes the conversion of homocysteine (HCY) to the essential amino acid methionine, utilizing a methyl group derived from 5-methyltetrahydrofolate.
This material causes defection of methionine synthase that converts homocysteine to methionine and there for decreases concentration of homocysteine [2].
6) During this period, cobalamin-dependent enzymes, namely methionine synthase are inhibited, the ability of the cells to produce methionine from homocysteine is impaired, and consequently plasma homocysteine level increases.
6] insufficiency result in increased homocysteine concentrations because they are cofactors for methionine synthase and cystathionine synthase, respectively.
Folate is required for methionine synthase to convert dangerous homocysteine into the amino acid methionine, thus preventing the buildup of homocysteine.
The 5-MTHF generated then can be used in the remethylation of homocysteine (Hcy) to methionine, which is catalyzed by methionine synthase (MTR).
One is methionine synthase (MS), by which Hcy react with 5-methyl tetrahydrofolate (5mTHF) to become Met.
The genes they have looked at are involved in the intracellular transport (reduced folate carrier 1 or RFC1), and conversion ([gamma] glutamyl hydrolase or GGH) of methotrxate, metabolism of purine and pyrimidine (methylenetetrahydrofolate reductase or MTHFR, thymidylate synthase or TS, methionine synthase or MS, serine hydroxymethyltransferase I or SHMT 1 , aminoimidazol carboxamide ribinucleotide transformylase or ATIC, methionine synthase reductase or MTRR) and efflux of the drug (multidrug resistance protein 1 or MDR1).
Objective: In this study, we investigated whether methionine synthase (MTR) A2756G and methionine synthase reductase (MTRR) A66G gene polymorphisms were related with infertility.
In most tissues, the remethylation of homocysteine is catalyzed by methionine synthase (MS), which uses [B.