Crystallization and preliminary diffraction studies of firefly luciferase from Photinus pyralis.

Firefly luciferase is a 62 kDa molecular weight enzyme which catalyzes a light-emitting reaction. Crystals of Photinus pyralis luciferase have been obtained by the microbatch technique, using polyethylene glycol as a precipitating agent. Firefly luciferase crystallizes as long needles which belong to the tetragonal space group P4(1)2(1)2, with cell dimensions a = 119.5, b = 119.5, c = 95.4 A. One molecule is present in the asymmetric unit. Diffracted intensities beyond 2.0 A resolution have been measured from frozen crystals using synchrotron radiation.