Crystallization, X-ray diffraction and oligomeric characterization of arginine decarboxylase from Yersinia pestis, a key polyamine biosynthetic enzyme.

Arginine decarboxylase (ADC) is a 70 kDa pyridoxal-5'-phosphate (PLP) dependent enzyme that controls an alternative step in the biosynthesis of polyamines in some bacteria and plants. Crystals of ADC were flash-cooled and diffracted to 3.0 A resolution using a synchrotron-radiation source. Crystals of ADC are monoclinic, with four monomers in the asymmetric unit. Light-scattering data reveals that the enzyme forms dimers in solution. The rotation function suggests the presence of two dimers in the asymmetric unit. Heavy-atom searches have identified PCMBS as forming a mercury derivative.