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. Author manuscript; available in PMC: 2010 Apr 24.
Published in final edited form as: Mol Cell. 2009 Apr 24;34(2):250–256. doi: 10.1016/j.molcel.2009.03.014

Figure 3. Retromobility, ppGpp levels, and the stringent response.

Figure 3

A. Retrohoming in mutants of the stringent response. Retrohoming frequency in mutant hosts was determined relative to “wild-type” MC1061 (relA1 spoT1), using the plasmid-to-chromosome assay (Fig. 1A), with the homing site located in the dedE gene. B. Levels of ppGpp in wild-type BL21(λDE3) and isogenic ΔrelA ΔspoT hosts. Lanes 1, 2 and 3 contain 0, 0.2 and 2 mg/ml SHX, respectively. Levels of ppGpp relative to GTP, expressed as ppGpp (100)/(ppGpp + GTP) were 22, 29 and 67 for WT and 4, 4 and 3 for ΔrelA ΔspoT (lanes 1–3). Results for the ΔrelA were similar to the ΔrelA ΔspoT host (not shown). C. Induction of retrotransposition (RTP) and retrohoming (RH) in mutants. Measurements were in BL21(λDE3) after treatment with 1 mg/ml SHX, and fold-increases were plotted relative to untreated samples (n = 3; standard deviations shown as error bars).