The stringent response blocks DNA replication outside the ori region in Bacillus subtilis and at the origin in Escherichia coli.

摘要: When the Bacillus subtilis dnaB37 mutant, defective in initiation, is returned to permissive temperature after growth at 45 °C, DNA replication synchronized. Under these conditions, we have shown previously that inhibited when Stringent Response induced by amino acid analogue, arginine hydroxamate. We now shown, using DNA-DNA hybridization analysis, substantial of oriC region nevertheless occurs during Response, and inhibition therefore implemented downstream from origin. On left arm, continues for least 190 × 103 base-pairs gnt gene a similar distance on right arm gerD gene. lifted, resumed both arms, confirming regulated post-initiation level B. subtilis. Resumption synthesis following lifting did not require protein or RNA initiation DnaB. suggest, therefore, specific control region, involving Control sites, facilitate reversible fork movement origin via modifications replisome component Response. In contrast, Escherichia coli, induction appears block itself. No was detected and, upon occurred oriC. Post-initiation results duplication many key genes involved sporulation. discuss possibility such might be linked differentiation this organism.