Fig. 1.

Potential mechanisms for the phosphorylation-mediated activation of OmpR-regulated transcription. Scheme A) Standard mechanism of RR transcriptional activation.^8–10 Schemes B and C) Mechanisms of OmpR transcriptional activation proposed previously.^13,18 Blue ovals and starbursts represent OmpR receiver domains in inactive and active conformational states, respectively. Red arrows represent OmpR DNA-binding domains and DNA is depicted in green. Pink circles and yellow circles represent phosphoryl group donors and phosphoryl groups, respectively.