CheW-only linkers can explain the large enhancement in cooperativity with increasing [W].

(A,B) Modeled dose-response curves for different levels of expression of CheW (A) and CheA (B) as multiples of wild-type levels [W]0 and [A]0, respectively. (C,D) Experimental results in gray are superimposed with parameters inferred from Hill curves fitted to the model outcome. Parameters for variation in [W] and [A] are shown in panels (C) and (D), respectively. Model parameters: Δϵ(QEQE) = −1.79, , , ρW = 3.52, ρA = 4.45, , , , and J = −4.07. The data for variations in CheA and CheW levels was fitted with receptor densities ρW and ρA, respectively.