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Members of this family while most probably evolutionary related, do not share extensive regions of sequence similarities. The proteins contain a conservedlysine residue which is known, in mouse ODC to be the site of attachment of the pyridoxal-phosphate group. The proteins also contain a stretch of three consecutive glycine residues and has been proposed to be part of a substrate-binding region.
Poulin R, Lu L, Ackermann B, Bey P, Pegg AE (January 1992). "Mechanism of the irreversible inactivation of mouse ornithine decarboxylase by alpha-difluoromethylornithine. Characterization of sequences at the inhibitor and coenzyme binding sites". J. Biol. Chem. 267 (1): 150–8. PMID1730582.