Crystallization and preliminary X-ray diffraction studies of photolyase (photoreactivating enzyme) from the cyanobacterium Anacystis nidulans.

Photolyase (photoreactivating enzyme) from the cyanobacterium Anacystis nidulans was crystallized by the hanging drop vapor diffusion procedure using ammonium sulfate as a precipitant. The pale-yellow crystals were grown to a size of 0.4 mm in length and 0.1 mm in diameter. They belong to the tetragonal space group P4(1)2(1)2 or P4(3)2(1)2 with unit cell dimensions of a = b = 90.7 A and c = 135 A. Assuming that the asymmetric unit contains one molecule, the Vm value is calculated as 2.6 A3/dalton. The crystals are stable towards X-ray exposure and diffract beyond 2.5 A resolution.