Table 1.

Effector molecule binding to P_II variants R9L and K58M

	Kd1, μM	Kd2, μM	Kd3, μM
2-OG (+1 mM ATP)
R9L	441 ± 40	123 ± 7	509 ± 116
K58M	ND	ND	ND
(WT)	(5.1 ± 4.0)	(11.1 ± 1.8)	(106.7 ± 14.8)
ATP
R9L	NM	NM	NM
K58M	10 ± 5	262 ± 136	31 ± 15
(WT)	(4.0 ± 0.1)	(12.5 ± 0.9)	(47.4 ± 21.9)

Values correspond to the mean of two independent experiments ± SEM. The raw data were fitted by using a three-site binding model for a P_II trimer. For comparison, the original data for WT P_II protein are given in parentheses. ND, not detectable; NM, not measured.