[Isolation and some properties of restriction endonuclease from Bacillus amyloliquefaciens]

A partially purified preparation of restriction endonuclease Bam I was isolated from the cells of Bacillus amyloliquefaciens. The purification procedure was a modification of a method described by Wilson and Young. Isolation and purification of the enzyme involved disruption of the cells by ultrasonication, treatment with streptomycin sulfate, fractionation by ammonium sulfate, chromatography on DEAE-cellulose and hydroxylapatite and rechromatography on DEAE-cellulose. Restrictase Bam I splits the linear double-chain DNA molecule of phage gamma into six fragments. The enzyme retained its stability under storage on the ice for 1,5--2 months in a Na- or K-phosphate buffer with beta-mercaptoethanol (10 mM).