The repressor–antirepressor complex AppA–PpsR is a transcriptional regulator that permits Rhodobacter to switch between photosynthesis and respiration in response to light and oxygen. A combination of crystallography, hydrogen/deuterium-exchange MS and binding assays shows how illumination reduces the affinity of the complex for DNA and provides insight into the mechanism of signal transduction by photoreceptors.
- Andreas Winkler
- Udo Heintz
- Ilme Schlichting