Members of his family are involved in the 1,2 rearrangement of the terminal amino group of DL-lysine and of L-beta-lysine, using adenosylcobalamin (AdoCbl) and pyridoxal-5'-phosphate as co-factors. The structure is predominantly a PLP-binding TIM barrel domain, with several additional alpha-helices and beta-strands at the N and C termini. These helices and strands form an intertwined accessory clamp structure that wraps around the sides of the TIM barrel and extends up toward the Ado ligand of the Cbl co-factor, providing most of the interactions observed between the protein and the Ado ligand of the Cbl, suggesting that its role is mainly in stabilising AdoCbl in the precatalytic resting state [1]. This is a TIM-barrel domain.

1: Large-scale domain dynamics and adenosylcobalamin reorientation orchestrate radical catalysis in ornithine 4,5-aminomutase. Wolthers KR, Levy C, Scrutton NS, Leys D; J Biol Chem. 2010;285:13942-13950. PMID:20106986