FIGURE 5.

Heme effect on the transcription levels of PpsR-regulated genes. A, PpsR-regulated photosynthesis and tetrapyrrole biosynthesis genes. The detailed diagram is described in supplemental Fig. 5. B, changes in relative transcription level of various PpsR-regulated genes in wild-type R. sphaeroides culture after addition of heme to the culture. After 20 min of starvation, 25 μm heme was added into the culture, and the samples were taken after another 20 min of incubation and normalized (supplemental Fig. 6). Data shown are mean ± S.E. (error bars). C, similar to B with the exception that mRNA levels were analyzed in the ppsR deletion strain, PPSR1.