Crystallization and preliminary X-ray crystallographic studies of phosphopantetheine adenylyltransferase from Helicobacter pylori

Phosphopantetheine adenylyltransferase (PPAT; EC 2.7.7.3) is an essential enzyme in the coenzyme A (CoA) biosynthetic pathway and catalyzes the reversible transfer of an adenylyl group from ATP to 4′-­phosphopantetheine to form 3′-dephospho-CoA. PPAT from Helicobacter pylori has been overexpressed in Escherichia coli and crystallized at 296 K using sodium chloride as a precipitant by the hanging-drop vapour-diffusion method. X-ray diffraction data have been collected to 2.00 Å resolution at 100 K using synchrotron radiation. The crystals belong to the trigonal space group P3₁21 or P3₂21, with unit-cell parameters a = b = 80.50, c = 143.05 Å, α = β = 90, γ = 120°. Six monomers of PPAT are likely to be present in the asymmetric unit, giving a V_M of 2.39 ų Da⁻¹ and a solvent content of 49%.