Expression, crystallization and preliminary crystallographic study of octaprenyl pyrophosphate synthase from Helicobacter pylori.

Octaprenyl pyrophosphate synthase (OPPs) is involved in the synthesis of the side chains of ubiquinone and menaquinone and catalyzes consecutive condensation reactions of farnesyl pyrophosphate with isopentenyl pyrophosphate to generate polyprenyl pyrophosphate and pyrophosphate. In order to investigate the roles played by OPPs in the metabolism of ubiquinone and menaquinone and the enzymatic mechanisms of these enzymes, analysis of the structure-function relationship of OPPs from Helicobacter pylori was initiated. The gene for OPPs was cloned, the protein was expressed, purified and crystallized and a diffraction data set was collected to 2.00 Å resolution. The crystals belonged to space group P4(1)2(1)2 or P4(3)2(1)2, with unit-cell parameters a = b = 109.33, c = 103.41 Å.