Fluctuation-response relationships. (A) Variance of CheY-P fluctuations (normalised by the squared adapted CheY-P value) as a function of adapted CheY-P value for varying adaptation rates γ
(solid line) and γ
(dashed line) and total CheY concentration (dotted line). The filled circle marks the point, where parameters for the three parameter variations coincide. (B) Adaptation time, calculated as (λ1∂A/∂M)-1, plotted against the variance of CheY-P fluctuations. Adapted CheY-P concentration of 5μM is indicated by the open circles. Legend is the same as in (A). Our parameters are given in Additional File 1. (Inset) Variance of CheY-P concentrations plotted against the adaptation time as extracted from measurements of motor rotation by Park et al. . The line is a linear fit through the data.