FIGURE 3.
Heme regulates PpsR-DNA binding. PpsR or its mutant was incubated with 2-fold of heme for 20 min before adding DNA when needed. 10 nm probe was used to bind PpsR unless noted otherwise. A, effect of heme on wild-type PpsR-puc interaction under oxidizing conditions. B, effect of heme on wild-type PpsR-puc interaction under reducing conditions. C, effect of heme on the PpsRH275A-puc interaction under oxidizing conditions. D, effect of heme on the PpsRH275A-puc interaction under reducing conditions. E, effect of heme on the PpsRC424A-puc interaction under oxidizing conditions.