Purification, crystallization and preliminary X-ray analysis of the 3-phosphoglycerate kinase from Bacillus stearothermophilus.

As part of a programme investigating the molecular basis of thermal stability in proteins we have isolated and characterized the thermally stable 3-phosphoglycerate kinase (PGK) from Bacillus stearothermophilus NCA 1503. The B. stearothermophilus PGK has been crystallized in a form suitable for X-ray diffraction analysis. Crystals which diffract to greater than 1.8 A resolution have been grown in the presence of the nucleotide substrate, MgATP, using polyethylene glycol (PEG 600) as a precipitant. The best crystals have been obtained using "seeding" techniques and are monoclinic, space group P2(1), with cell dimensions a = 40.5 A, b = 74.0 A, c = 68.5 A and beta = 99.8 degrees.