Fig. 2.
FRET responses (Y/C ratio) of cheR cheB cells to stepwise addition of chemical attractants. The attractants were added at the times indicated by the arrows. (a) CheY-YFP/CheZ-CFP FRET responses to 1 mM MeAsp (weak attractant). (b) CheY-YFP/CFP-FliM FRET responses to 2 mM MeAsp + 0.5 mM L-serine (strong attractant).