The biotinyl-domain or biotin carboxyl carrier protein (BCCP) domain is present in all biotin-dependent enzymes, such as acetyl-CoA carboxylase, pyruvate carboxylase, propionyl-CoA carboxylase, methylcrotonyl-CoA carboxylase, geranyl-CoA carboxylase, oxaloacetate decarboxylase, methylmalonyl-CoA decarboxylase, transcarboxylase and urea amidolyase. This domain functions in transferring CO2 from one subsite to another, allowing carboxylation, decarboxylation, or transcarboxylation. During this process, biotin is covalently attached to a specific lysine.
Lu S et al.(2020). "CDD/SPARCLE: the conserved domain database in 2020.",