ATP requirement for in vitro DNA synthesis in permeable cells of Bacillus brevis

DNA synthesis in permeable cells of Bacillus brevis is almost completely dependent on the presence of ATP. Nevertheless, DNA synthesis in this system reflects primarily DNA repair rather than replication, as shown by the response to replication inhibitors, density shift experiments, and product size analysis. The apparent dependence of DNA synthesis on ATP was due to the stabilization of the deoxyribonucleoside triphosphate pools against degradation. These observations indicate that dependence of DNA synthesis on ATP is not a sufficient criterion for semiconservative DNA replication.