Crystallization and preliminary neutron diffraction studies of ADP-ribose pyrophosphatase-I from HB8

Okazaki, Nobuo; Adachi, Motoyasu; Tamada, Taro; Kurihara, Kazuo; Oga, Takushi*; Kamiya, Nobuo*; Kuramitsu, Seiki*; Kuroki, Ryota

ADP-ribose pyrophosphatase-I from HB8 (ADPRase-I) prevents the intracellular accumulation of ADP-ribose by hydrolyzing it to AMP and ribose 5'-phosphate. To understand the catalytic mechanism of ADPRase-I, it is necessary to investigate the role of glutamates and metal ions as well as the coordination of water molecules located at the active site. A macroseeding method was developed in order to obtain a large ADPRase-I crystal which was suitable for a neutron diffraction study to provide structural information. Neutron and X-ray diffraction experiments were performed at room temperature using the same crystal. The crystal diffracted to 2.1 and 1.5 resolution in the neutron and X-ray diffraction experiments, respectively. The crystal belonged to the primitive space group 321, with unit-cell parameters = = 50.7, = 119 .