Cloning and mapping of a cDNA for methionine synthase reductase, a flavoprotein defective in patients with homocystinuria.

ABSTRACT: Methionine synthase catalyzes the remethylation of homocysteine to methionine via a reaction in which methylcobalamin serves as an intermediate methyl carrier. Over time, the cob(I)alamin cofactor of methionine synthase becomes oxidized to cob(II)alamin rendering the enzyme inactive. Regeneration of functional enzyme requires reductive methylation via a reaction in which S-adenosylmethionine is utilized as a methyl donor. Patients of the cblE complementation group of disorders of folate/cobalamin metabolism who are defective in reductive activation of methionine synthase exhibit megaloblastic anemia, developmental delay, hyperhomocysteinemia, and hypomethioninemia. Using consensus sequences to predicted binding sites for FMN, FAD, and NADPH, we have cloned a cDNA corresponding to the "meth

SUBMITTER: Leclerc D 

PROVIDER: S-EPMC19694 | biostudies-literature | 1998 Mar

REPOSITORIES: biostudies-literature