(methionine synthase) reductase

[methionine synthase] reductase
Identifiers
EC number	1.16.1.8
CAS number	207004-87-3
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 / EGO
Search PMC articles PubMed articles

In enzymology, a [methionine synthase] reductase (EC 1.16.1.8) is an enzyme that catalyzes the chemical reaction

2 [methionine synthase]-methylcob(I)alamin + 2 S-adenosylhomocysteine + NADP⁺ $\rightleftharpoons$ 2 [methionine synthase]-cob(I)alamin + NADPH + H⁺ + 2 S-adenosyl-L-methionine

The 3 substrates of this enzyme are methionine synthase-methylcob(I)alamin, S-adenosylhomocysteine, and NADP⁺, whereas its 4 products are methionine synthase-cob(I)alamin, NADPH, H⁺, and S-adenosyl-L-methionine.

This enzyme belongs to the family of oxidoreductases, to be specific those oxidizing metal ion with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is [methionine synthase]-methylcob(I)alamin,S-adenosylhomocysteine:NADP+ oxidoreductase. Other names in common use include methionine synthase cob(II)alamin reductase (methylating), methionine synthase reductase, [methionine synthase]-cobalamin methyltransferase (cob(II)alamin, and reducing). It employs one cofactor, flavoprotein.

References

• Rommens JM, Scherer SW, Rosenblatt DS, Gravel RA (1998). "Cloning and mapping of a cDNA for methionine synthase reductase, a flavoprotein defective in patients with homocystinuria". Proc. Natl. Acad. Sci. U. S. A. 95 (6): 3059–64. doi:10.1073/pnas.95.6.3059. PMC 19694. PMID 9501215. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=19694. 
• Olteanu H, Banerjee R (2001). "Human methionine synthase reductase, a soluble P-450 reductase-like dual flavoprotein, is sufficient for NADPH-dependent methionine synthase activation". J. Biol. Chem. 276 (38): 35558–63. doi:10.1074/jbc.M103707200. PMID 11466310. 
• Olteanu H, Munson T, Banerjee R (2002). "Differences in the efficiency of reductive activation of methionine synthase and exogenous electron acceptors between the common polymorphic variants of human methionine synthase reductase". Biochemistry. 41 (45): 13378–85. doi:10.1021/bi020536s. PMID 12416982.