These enzymes consist of several conserveddomains.
The N-terminal domain has a flavodoxin-like fold, and is termed the "wing" domain because of its position in the overall 3D structure. Ornithine decarboxylase from Lactobacillus 30a (L30a OrnDC) is representative of the large, pyridoxal-5'-phosphate-dependent decarboxylases that act on lysine, arginine or ornithine. The crystal structure of the L30a OrnDC has been solved to 3.0 A resolution. Six dimers related by C6 symmetry compose the enzymatically active dodecamer (approximately 106Da). Each monomer of L30a OrnDC can be described in terms of five sequential foldingdomains. The amino-terminal domain, residues 1 to 107, consists of a five-stranded beta-sheet termed the "wing" domain. Two wing domains of each dimer project inward towards the centre of the dodecamer and contribute to dodecamer stabilisation.[2]
The major domain contains a conserved lysine residue, which is the site of attachment of the pyridoxal-phosphate group.[2]
^ abMomany C, Ernst S, Ghosh R, Chang NL, Hackert ML (October 1995). "Crystallographic structure of a PLP-dependent ornithine decarboxylase from Lactobacillus 30a to 3.0 A resolution". J. Mol. Biol. 252 (5): 643–55. doi:10.1006/jmbi.1995.0526. PMID7563080.