Methylmalonyl-CoA

Methylmalonyl-CoA is the coenzyme A linked form of methylmalonic acid. Methylmalonyl-CoA is formed from propionyl-CoA by propionyl-CoA carboxylase by help of biotin (vitamin B7). It is converted into succinyl-CoA by methylmalonyl-CoA mutase, in a reaction that requires vitamin B12 as a cofactor. In this way, it enters the Krebs cycle, and is thus part of one of the anaplerotic reactions. The following diagram demonstrates the aforementioned reactions:


 * Propionyl CoA → Methylmalonyl CoA → Succinyl CoA