Crystallization and preliminary crystallographic analysis of molybdenum-cofactor biosynthesis protein C from Thermus thermophilus.

The gram-negative aerobic eubacterium Thermus thermophilus is an extremely important thermophilic microorganism that was originally isolated from a thermal vent environment in Japan. The molybdenum cofactor in this organism is considered to be an essential component required by enzymes that catalyze diverse key reactions in the global metabolism of carbon, nitrogen and sulfur. The molybdenum-cofactor biosynthesis protein C derived from T. thermophilus was crystallized in two different space groups. Crystals obtained using the first crystallization condition belong to the monoclinic space group P2(1), with unit-cell parameters a = 64.81, b = 109.84, c = 115.19 A, beta = 104.9 degrees; the crystal diffracted to a resolution of 1.9 A. The other crystal form belonged to space group R32, with unit-cell parameters a = b = 106.57, c = 59.25 A, and diffracted to 1.75 A resolution. Preliminary calculations reveal that the asymmetric unit contains 12 monomers and one monomer for the crystals belonging to space group P2(1) and R32, respectively.