Fig. 5.

FRET analyses of FP–OmpR interaction.

A. Phosphorylation-activated FRET of FP–OmpR hybrids. Equal concentrations (2 μM each) of CFP–OmpR and YFP–OmpR were phosphorylated by phosphoramidate. The fitted curve (solid line) indicates a rate constant of 0.38 × 10⁻³ s⁻¹.

B. Effect of DNA on FRET between FP–OmpR hybrids. C1 DNA was titrated into the mixture of 2 μM CFP–OmpR and 2 μM YFP–OmpR (solid squares) or 2 μM CFP–OmpR only (open circles) in the absence of phosphorylation.