Table 1.

Autophosphorylation and autodephosphorylation rate constants of CheY variants.

CheY designationa	Amino acid at position		kphos/KS (M−1s−1)b		kdephos (min−1)c
	D+2	T+2	Phosphoramidate	Acetyl phosphate
DX set (HAD mimics)
DR	D	R	820 ± 26	3.9 ± 0.4	20 ± 1.7
DK	D	K	170 ± 3	5.7 ± 0.5	2.8 ± 0.06
DQ	D	Q	13 ± 0.2	1.5 ± 0.05	4.8 ± 0.03
DY	D	Y	130 ± 10	0.5 ± 0.05	0.7 ± 0.05
DT	D	T	4.1 ± 0.05	0.3 ± 0.1	1.7 ± 0.02
DE	D	E	3.7 ± 0.55d	< 0.2d	5.5 ± 0.4e
NX set
NR	N	R	93 ± 18d	62 ± 5.5d	0.69 ± 0.04e
NK	N	K	60 ± 7.3d	42 ± 0.9d	1.2 ± 0.3e
NQ	N	Q	19 ± 3d	36 ± 1.8d	3.9f
NY	N	Y	240 ± 34d	13 ± 1.9d	0.26 ± 0.01e
NA	N	A	10 ± 0.8d	18 ± 2.0d	1.5f
wild type	N	E	9.2 ± 0.9	10 ± 0.7	3.2 ± 0.2

^aCheY variants are referred to in the text by ‘CheY’ followed by the single letter codes for the amino acids at positions D+2 and T+2 (CheY residues 59 and 89).

^bMean and standard deviation of autophosphorylation rate constants (n=3). See Experimental Procedures or footnote d where indicated.

^cMean and standard deviation of autodephosphorylation rate constants (n=3). See Experimental Procedures or footnotes e or f where indicated.

^dThomas et al.²³

^eThomas et al.²²

^fSilversmith et al.⁷⁹