Crystallization and preliminary X-ray crystallographic studies of the thermoactive pullulanase type I, hydrolyzing α-1,6 glycosidic linkages, from Fervidobacterium pennivorans Ven5

Crystals of the thermoactive recombinant F. pennivorans type I pullulanase, purified from the supernatant of a Bacillus subtilis culture, have been obtained by the vapour-diffusion method in the presence of the inhibitor β-cyclodextrin (2 mM) by mixing protein (15 mg ml⁻¹) with an equal volume of crystallization solution containing 0.1 M bis–tris propane pH 6.5, 50 mM MgCl₂ and 15% polyethylene glycol 3350. Crystals diffracted to 3.0 Å using conventional Cu Kα radiation and belong to space group P2₁2₁2₁, with unit-cell parameters a = 76.8, b = 96.2, c = 98.5 Å. The asymmetric unit contains one monomer. A preliminary 26% complete data set has been collected at 2.2 Å resolution using synchrotron radiation.