Crystallization and preliminary X-ray diffraction analysis of NADP-dependent glyceraldehyde-3-phosphate dehydrogenase of Synechococcus PCC 7942

The NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of Syne chococcus PCC 7942 was crystallized in two different forms by the hanging-d rop vapour-diffusion method using ammonium sulfate as a precipitant. Form I crystals were hexagonal, space group P6(5) or P6(1), with unit-cell parame ters a = b = 91.1, c = 428.6 Angstrom, gamma = 120 degrees. Form II crystal s were monoclinic, space group C2, with unit-cell parameters a = 152.3, b= 80.9, c = 213.6 Angstrom, beta= 103.1 degrees. Native data were collected f rom a frozen crystal of form I to a resolution of 2.8 Angstrom using synchr otron radiation at SPring-8, whereas form II crystals were easily damaged b y radiation at room temperature and increased mosaicity in cryoprotectant s olutions. A molecular-replacement solution of the form I crystal was obtain ed in space group P6(5) using the program AMoRe and the structure of the NA D-dependent GAPDH from Bacillus stearothermophilus.