| Primary Identifier | IPR032037 | Type | Family |
| Short Name | MMACHC |
| description | MMACHC, also known as Cyanocobalamin reductase / alkylcobalamin dealkylase, is involved in the intracellular processing of vitamin B12 by catalyzing two reactions: the reductive decyanation of cyanocobalamin in the presence of a flavoprotein oxidoreductase and the dealkylation of alkylcobalamins through the nucleophilic displacement of the alkyl group by glutathione [, ]. Mutations in the MMACHC gene have been linked to a disease known as Methylmalonic aciduria and homocystinuria, cblC type (OMIM 277400), the most common inborn error of vitamin B(12) (cobalamin) metabolism. The C-terminal region of this protein folds similarly to TonB, a bacterial protein involved in energy transduction for cobalamin uptake [].The structure of MMACHC reveals it to be the most divergent member of the NADPH-dependent flavin reductase family that can use FMN or FAD to catalyze reductive decyanation; it is also the first enzyme with glutathione transferase (GST) activity that is unrelated to the GST superfamily in structure and sequence []. |
