Purification and initial crystallization studies of a DnaB intein from Synechocystis sp. PCC 6803

A 154-residue mini-intein from the dnaB gene of Synechocystis sp. PCC 6803 (Ssp DnaB intein) has been purified and crystallized using PEG 4000 as a precipitant. The crystal belongs to space group P3₁21 or P3₂21, with unit-cell parameters a = b = 58.2, c = 70.3 Å. It has one molecule per asymmetric unit and diffracts to beyond 2.0 Å under cryoconditions (100 K) using a rotating copper anode X-ray generator.