MMACHC gene: role in Vitamin B12 metabolism

MMACHC (Methylmalonic aciduria and homocystinuria type C protein) gene is a Protein Coding gene. The MMACHC gene provides instructions for making a protein that helps convert vitamin B12 (also called cobalamin) into one of two molecules, adenosylcobalamin (AdoCbl) or methylcobalamin (MeCbl).

AdoCbl is required for the normal function of an enzyme known as methylmalonyl CoA mutase. This enzyme helps break down certain protein building blocks (amino acids), fats (lipids), and cholesterol. AdoCbl is called a cofactor because it helps methylmalonyl CoA mutase carry out its function. Methylmalonyl CoA mutase catalyses the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the genera-tion of radicals that allow isomerization of the substrate.

MeCbl is also a cofactor, but for an enzyme known as methionine synthase. This enzyme converts the amino acid homocysteine to another amino acid, methionine. The body uses methionine to make proteins and other important compounds. Methionine is an aliphatic, sulfur-containing, essential amino acid, and a precursor of succinyl-CoA, homocysteine, cysteine, creatine, and carnitine. Recent research has demonstrated that methionine can regulate metabolic processes, the innate immune system, and digestive functioning.

Cobalamin C (cblC) deficiency, the most common inborn error of intracellular cobalamin metabolism, is caused by mutations in MMACHC, a gene responsible for the processing and intracellular trafficking of vitamin B12.

Diseases associated with MMACHC include Methylmalonic Aciduria And Homocystinuria, Cblc Type and Methylmalonic Acidemia With Homocystinuria. Among its related pathways are Diseases of metabolism and Metabolism of water-soluble vitamins and cofactors.
MMACHC gene: role in Vitamin B12 metabolism