Cleavage of Coenzyme B12 by Methylmalonyl Coenzyme A Mutase
نویسندگان
چکیده
منابع مشابه
The Absolute Configuration of Methylmalonyl Coenzyme A and Stereochemistry of the Methylmalonyl Coenzyme A Mutase Reaction*
Rropionyl coenzyme A was carboxylated with epimerasefree carboxylase, and the resulting methylmalonyl coenzyme A (a) was reduced with Raney nickel. Isolation of (-)(R)-P-hydroxyisobutyric acid N-phenylcarbamate (11) from the reaction mixture showed that methylmalonyl coenzyme A (a) has the (S) configuration. Propionyl coenzyme A was also converted to deuteriosuccinate with a DrO extract of a be...
متن کاملActivation of methylmalonyl-Coenzyme A mutase by MeaB
In mammalian cells, only two enzymes are known to require vitamin B12 (cobalamin, Cbl) derivatives as a cofactor: methionine synthase, a cytosolic enzyme, which uses methylcobalamin, and methylmalonyl-coenzyme A mutase (MCM), a mitochondrial enzyme, which uses 5’-deoxyadenosylcobalamin (AdoCbl) (1). The latter enzyme has a broad distribution among living organisms and is found in both bacteria ...
متن کاملDirect Hydrogen Transfer by Methylmalonyl Coenzyme a Mutase.
In this scheme, the racemase involves a rearrangement of the hydrogen about the asymmetrical carbon (6,7), while the mutase reaction involves an intramolecular migration (8, 9) of the thioester group (l&12). Two approaches are available to determine the source of the hydrogen that arises on carbon 3 of succinyl-CoA as a result of methylmalonyl-Coil mutase action. The first or indirect approach,...
متن کاملImportance of the histidine ligand to coenzyme B12 in the reaction catalyzed by methylmalonyl-CoA mutase.
Methylmalonyl-CoA mutase is an adenosylcobalamin (AdoCbl)-dependent enzyme that catalyzes the rearrangement of methylmalonyl-CoA to succinyl-CoA. The crystal structure of this protein revealed that binding of the cofactor is accompanied by a significant conformational change in which dimethylbenzimidazole, the lower axial ligand to the cobalt in solution, is replaced by His-610 donated by the a...
متن کاملMeaA, a putative coenzyme B12-dependent mutase, provides methylmalonyl coenzyme A for monensin biosynthesis in Streptomyces cinnamonensis.
The ratio of the major monensin analogs produced by Streptomyces cinnamonensis is dependent upon the relative levels of the biosynthetic precursors methylmalonyl-coenzyme A (CoA) (monensin A and monensin B) and ethylmalonyl-CoA (monensin A). The meaA gene of this organism was cloned and sequenced and was shown to encode a putative 74-kDa protein with significant amino acid sequence identity to ...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1973
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(19)44319-6