[Expression of cloned gene for methyltransferase from Bacillus subtilis bacteriophage SPbetaB]

Expression of the methyltransferase gene from Bacillus subtilis lysogenizing phage SP beta B was studied by analyzing the sensitivity of the hybrid plasmid DNAs to restriction by the enzymes BspRI, Hpall and Mspl. The gene produces the methylase M. BsuP beta BI with specificity for 5'-GGCC. The fragment carrying the SP beta B derived gene also directs the synthesis in E. coli of a second methylase activity (M. BsuP beta BII) with 5'-CCGG specificity. Indirect evidence suggests that the two SP beta B modification activities are encoded by the same gene.