Studies on in vitro Replication of Bacillus subtilis DNA

Replication of the chromosomes in the cell in direct coordination with cell division is the basic feature of mitosis. In simple forms like bacteria, with one chromosome and no nuclear membrane, chromosome r plication is supposed to occur at a site on the cell wall-membrane (Jacob et a]., 1963). The process of chromosome r plication in bacterial cells has been shown to be semiconservative and proceeds with simultaneous replication of both strands of the molecule, starting from one end (Cairns, 1963; Meselson and Stahl, 1958; Sueoka, 1966). We do not know the enzymatic basis for such a process of synthesis. Highly purified polymerase from E. coli with double-stranded transforming DNA as template generates a nondenaturable,