Crystallization and preliminary X-ray crystallographic analysis of type II dehydroquinase from Helicobacter pylori

The enzyme 3-dehydroquinase catalyzes the interconversion of 3-­dehydroquinate and 3-dehydroshikimate. The enzymes are classified into two groups, type I and type II, which have different biochemical and biophysical properties and act with different mechanisms. The type II dehydroquinase of Helicobacter pylori, a dodecameric enzyme, was overexpressed in Escherichia coli. The recombinant protein has been crystallized at 296 K using polyethylene glycol (PEG) 4000 as a precipitant. Native X-ray diffraction data have been collected to 2.5 Å resolution using synchrotron radiation. The crystals are cubic and belong to the space group P4₂32, with unit-cell parameters a = b = c = 98.91 Å. The asymmetric unit contains one subunit of recombinant type II dehydroquinase, with a corresponding V_M of 2.18 Å³ Da^-1 and a solvent content of 43.6%.