All of the members in this family are biotin dependent carboxylases. The carboxyl transferase domain carries out the following reaction; transcarboxylation from biotin to an acceptor molecule. There are two recognized types of carboxyl transferase. One of them uses acyl-CoA and the other uses 2-oxoacid as the acceptor molecule of carbon dioxide. All of the members in this family utilize acyl-CoA as the acceptor molecule.