[5] The C-terminal region of the product of the MMACHC gene is similar to TonB, a bacterial protein involved in energy transduction for cobalamin uptake.

[5] The MMACHC gene product catalyzes the decyanation of cyanocobalamin as well as the dealkylation of alkylcobalamins including methylcobalamin and adenosylcobalamin.

[7] The MMACHC gene product and cobalamin reductases enable the interconversion of cyano- and alkylcobalamins.

[8][9] Mutations are associated with combined homocystinuria and methylmalonic acidemia.

This article on a gene on human chromosome 1 is a stub.