H2AX and infection: Complementation of E. coli M1/5 ΔclbR with pBAD24-tetAp-clbR-rrnBt and complementation of the clbQ deletion mutant of E. coli M1/5 with pBAD24-tetAp-clbQ-rrnBt resulted in γ-H2AX levels in infected HeLa cells that corresponded to those observed upon infection with M1/5 derivatives overexpressing clbR and clbQ, respectively (Fig. 8B).