InterPro domain: IPR001095

This entry contains the alpha subunit the acetyl coenzyme A carboxylase complex ( 6.4.1.2 ). It catalyses the first step in the synthesis of long-chain fatty acids which involves the carboxylation of acetyl-CoA to malonyl-CoA. The acetyl-CoA carboxylase complex is a heterohexamer of biotin carboxyl carrier protein, biotin carboxylase and two non-identical carboxyl transferase subunits (alpha and beta) in a 2:2 association [ 1 ]. The reaction involves two steps:

Biotin carrier protein + ATP + HCO ₃ ^- -> Carboxybiotin carrier protein + ADP + P _i Carboxybiotin carrier protein + Acetyl-CoA -> Malonyl-CoA + Biotin carrier protein

1. The genes encoding the two carboxyltransferase subunits of Escherichia coli acetyl-CoA carboxylase. J. Biol. Chem. 267, 16841-7