Cloning, expression, purification, crystallization and preliminary X-ray crystallographic study of DHNA synthetase from Geobacillus kaustophilus

The aerobic Gram-positive bacterium Geobacillus kaustophilus is a bacillus species that was isolated from deep-sea sediment from the Mariana Trench. 1,4-­Dihydroxy-2-naphthoate (DHNA) synthetase plays a vital role in the biosynthesis of menaquinone (vitamin K₂) in this bacterium. DHNA synthetase from Geobacillus kaustophilus was crystallized in the orthorhombic space group C222₁, with unit-cell parameters a = 77.01, b = 130.66, c = 131.69 Å. The crystal diffracted to a resolution of 2.2 Å. Preliminary studies and molecular-replacement calculations reveal the presence of three monomers in the asymmetric unit.