Rapid Communication J. Biochem, 127, &-11 (2000) Crystallization and Preliminary X-Ray Crystallographic Studies of Thermus thermophilus HB8 MutM Protein Involved in Repairs of

MutM protein, which removes the oxidatively damaged DNA base product, 8-oxogua-nine (GO), has been crystallized by means of a hanging-drop vapor-diffusion procedure using polyethyleneglycol monomethylether 2000 as a precipitant in 2-(cyclohexylamino) ethanesulfonic acid (CEDES) buffer, pH9.8. The diffraction data derived from oscillation photographs indicate that the crystals belong to the monoclinic system and space group P2V The crystals have unit-cell dimensions of a = 45.4 A, 6 = 62.0 A, c = 99.7 A, and P = 90.8*. Assuming that the asymmetric unit contains two molecules, the Vm value was calculated to be 2.36 A3«Da"1. The crystals diffracted X-rays to at least 2.1 A resolution and were suitable for high-resolution X-ray crystal structure determination. Key words: crystallization, DNA repair enzyme, MutM protein, oxidative DNA damage