Expression, purification, and crystallization of restriction endonuclease PvuII with DNA containing its recognition site.

We have overexpressed the type II restriction endonuclease PvuII (R-PvuII) in E. coli, prepared large amounts of the homogeneous enzyme, and crystallized it with an oligonucleotide carrying a PvuII recognition site. The cocrystals are orthorhombic space group P2(1)2(1)2(1) with cell constants a = 95.8 A, b = 86.3 A, c = 48.5 A, and diffract X-rays to at least 2.7 A. There is a complex of two protein subunits and one oligonucleotide duplex in the asymmetric unit.