Different effects of ppGpp on Escherichia coli DNA replication in vivo and in vitro

▸ ppGpp, but not DksA, inhibits Escherichia coli DNA replication in vitro. ▸ ppGpp, but not DksA, inhibits E. coli DnaG primase activity in vitro. ▸ Elongation of E. coli DNA replication is not halted during the stringent response. ▸ Effects of ppGpp on DnaG primase activity may be masked in E. coli cells.