Acetyl-CoA carboxylase carboxyl transferase, beta subunit (IPR000438)

Short name: Acetyl_CoA_COase_Trfase_b_su

Overlapping homologous superfamilies

Family relationships



Fatty acid synthesis involves a set of reactions, commencing with carboxylation of acetyl-CoA to malonyl-CoA. This is an irreversible reaction, catalysed by the acetyl-CoA carboxylase complex (EC:; a heterohexamer of biotin carboxyl carrier protein, biotin carboxylase and two non-identical carboxyl transferase subunits (alpha and beta) in a 2:2 association [PMID: 1355089]. The reaction involves two steps:

  1. Biotin carrier protein + ATP + HCO3- = Carboxybiotin carrier protein + ADP + Pi
  2. Carboxybiotin carrier protein + Acetyl-CoA = Malonyl-CoA + Biotin carrier protein
In the first step, biotin carboxylase catalyses the carboxylation of the carrier protein to form an intermediate. Next, the transcarboxylase complex transfers the carboxyl group from the intermediate to acetyl-CoA forming malonyl-CoA.

GO terms

Biological Process

GO:0006633 fatty acid biosynthetic process

Molecular Function

GO:0003989 acetyl-CoA carboxylase activity

Cellular Component

GO:0009317 acetyl-CoA carboxylase complex

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.