Crystallization of a Mammalian Ornithine Decarboxylase

Crystals of truncated (A425- 461) pyridoxal-5'-phosphate (PLP)-dependent mouse ornithine decarboxylase (mOrnDC') have been obtained that diffract to 2.2 reso- lution (P2,2,2, a = 119.5 A, b = 74.3 A, c = 46.1 A). OrnDC produces putrescine, which is the precursor for the synthesis of polyamines in eu- karyotes. Regulation of activity and under- standing of the mechanism of action of this en- zyme may aid in the development of compounds against cancer. mOrnDC is a member of group IV PLP-dependent decarboxylases, for which there are no known representative structures. 0 1996 Wiley-Liss, Inc.