Fig. S7.

Dose–response parameter values of interface 2 mutants. Response parameters were derived from in vivo FRET kinase assays performed in strain UU2784, which lacks the sensory adaptation enzymes (CheR⁻ CheB⁻) and expresses only the Tsr chemoreceptor. CheA and CheW proteins were expressed from plasmid pPM25 derivatives in combination with the FRET reporter pair (CheY-YFP/CheZ-CFP) from plasmid pVS88. Normalized kinase activities at each serine test concentration were fitted to a multisite Hill equation to obtain K_1/2 and Hill coefficient values. The dashed line indicates average wild type values for K_1/2 (17 µM) and the Hill coefficient (17).