Overexpression, purification and crystallization ofBamHI endonuclease

Abstract
The type II restriction endonuclease Bam HI has been expressed In E. coli , producing 100-fold more enzyme than the wild type Bacillus amyloliquefaciens H strain. This high yield has facilitated purification to homogeneity of large amounts of the enzyme, along with its crystallization in a form which diffracts to at least 1.9 A in X-ray analysis.