Crystallization and X-ray diffraction measurements on recombinant molbindin, MopII, from Clostridium pasteurianum

Clostridium pasteurianum carries three genes termed mopI, II and III encodi ng three molbindin isoforms, one of which has been cloned, the gene product expressed in high yield and crystallized using the hanging-drop vapour-dif fusion method. Well ordered monoclinic crystals in two different crystal fo rms, both with space group C2, were obtained in the presence and absence of Na2MoO4 and Na2WO4. Ligand-bound MopII crystallized with polyethylene glyc ol (PEG) 400 as a precipitant, whereas apo MopII required PEG 6000. High-re solution diffraction data were collected for ligand-bound MopII structures using synchrotron radiation to 1.8 and 1.6 Angstrom resolution for the moly bdate and tungstate complexes, respectively. Data were collected on apoMopI I crystals to a resolution of 1.8 Angstrom in-house.