MMAAMethylmalonic aciduria type A protein, mitochondrial also known as MMAA is a protein that in humans is encoded by the MMAA gene.FunctionThe protein encoded by this gene is involved in the translocation of cobalamin into the mitochondrion, where it is used in the final steps of adenosylcobalamin synthesis. Adenosylcobalamin is a coenzyme required for the activity of methylmalonyl-CoA mutase.Clinical significanceMutations in the MMAA gene are associated with methylmalonic acidemia.