FIG. 2.

(Upper panel) R. sphaeroides PpsR regulon. Each gene is represented by a box colored according to its function. Green, bch genes; red, crt genes; blue, genes encoding structural polypeptides of photocomplexes; grey, genes encoding assembly factors or proteins of unknown function; orange, genes encoding regulatory factors; pink, genes encoding enzymes common to Bchl and ubiquinone biosynthesis; magenta, protoporphyrin IX biosynthesis genes. PpsR-binding sites are shown as red vertical arrows. Putative transcripts are shown as black horizontal arrows. Genes that are either known or predicted to be directly repressed by PpsR are circles. (Lower panels) Relative expression of PpsR-dependent genes measured by genechips (compared to that in the wild-type strain grown at high [20%] oxygen). Expression levels are according to the presented color scheme. The expression of every gene in 2.4.1 grown at high (20%) oxygen is assigned a value of 1 (data not shown).