TABLE 2.

Rate constants for phosphorylation and autodephosphorylation of CheY mutants at position 89

CheY	kobs for phosphorylation (s−1)a		kdephosph (s−1)b
	Acetyl phosphate (50 mM)	Phosphoramidate (50 mM)
Wild-type	0.46	0.61	0.065
E89Q	1.7	1.6	0.065
E89A	0.67	0.66	0.025

^ak_obs = k_phosp [phosphodonor]/K_s + k_dephosph (22). k_obs values were measured at 25°C.

^bk_dephosph values were measured at room temperature.