Figure 7

Comparison of SapB expression in M600 (relA+ ppGpp+) and M570 (relA- ppGpp-). (a) qRT-PCR confirms that transcription of sapB in the 48 h samples is approximately 40-fold increased as a result of relA mutation. (b) This is reflected in a large increase in SapB extracted from M570 (relA-) cells harvested after 48 h growth on MYM TE agar, as detected by Western blotting. Lanes 1, 2 and 3 indicate biological replicate samples. The average of three qRT-PCR determinations is shown, and standard deviations are marked with error bars. Western analysis was performed on biological duplicate samples, and a representative result is shown.