Propionyl-CoA carboxylase (PCC)

Propionyl-CoA carboxylase is a biotin-dependent mitochondrial enzyme that catalyzes the ATP-dependent carboxylation of propionyl-CoA to form D-methylmalonyl-CoA, a key step in the breakdown of certain amino acids (valine, isoleucine, methionine, threonine), odd-chain fatty acids, and cholesterol[1][5]. The enzyme functions as an alpha(6)beta(6) dodecamer composed of six alpha and six beta subunits encoded by the nuclear genes PCCA and PCCB respectively[2][6]. The reaction it catalyzes provides intermediates for gluconeogenesis via succinyl-CoA entry into the Krebs cycle[1]. Deficiency or dysfunction due to genetic mutations causes propionic acidemia—a severe inherited metabolic disorder characterized by accumulation of toxic metabolites leading to neurological damage and potentially fatal neonatal crises if untreated[5][2]. No approved drugs directly target this enzyme; current therapies focus on dietary management and supportive care for affected individuals.

Other names

Propionyl coenzyme A carboxylasePCCasePropanoyl-CoA:carbon dioxide ligasePCCA (alpha subunit gene)PCCB (beta subunit gene)