Crystallization and preliminary X-ray crystallographic analysis of UDP-N-acetylglucosamine acyltransferase from Helicobacter pylori

Lipid A, a constituent of lipopolysaccharides, is essential for the growth and virulence of most Gram-negative bacteria. This makes its biosynthetic enzymes potential targets for development of new antibacterial agents. The first step of lipid A biosynthesis is catalyzed by the enzyme UDP-N-acetylglucosamine acyltransferase (LpxA). LpxA from the pathogenic bacterium Helicobacter pylori has been overexpressed in Escherichia coli and crystallized at 297 K using ammonium sulfate and sodium/potassium tartrate as precipitants in the presence of a detergent. Diffraction data to 2.1 Å resolution have been collected from a native crystal. The crystal belongs to space group P6₃22, with unit-cell parameters a = b = 90.69, c = 148.20 Å. The asymmetric unit contains one subunit of LpxA, with a crystal volume per protein mass (V_M) of 2.87 ų Da^-1 and a solvent content of 57.1%.