Table 2. SMN^26–51–Gemin2^95–280 dissociation constants.

K_d values reported are the average of three to six individual binding titrations. The K_d value for SMN D44V in NP40-containing buffer at 4°C could not be determined precisely, but a lower limit of 4 μM could be established.

SMN26–51	Gemin2	Buffer*	Temperature (°C)	Kd (nM)
Wild-type	12–280	PBS	25	7.0±2.5
Wild-type	95–280	PBS	25	3.3±1.8
Wild-type	95–280	PBS, 300 mM NaCl	25	5.2±1.8
Wild-type	95–280	PBS, 600 mM NaCl	25	2.4±1.5
Wild-type	95–280	PBS	4	2.3±0.92
Wild-type	95–280	PBS+NP40	25	2.2±1.7
Wild-type	95–280	PBS+NP40	4	180±27
W34A	95–280	PBS	25	16±2.2
D35A	95–280	PBS	25	6.8±2.1
D36A	95–280	PBS	25	8.3±2.5
L39A	95–280	PBS	25	74±41
K41A	95–280	PBS	25	4.8±1.0
Y43A	95–280	PBS	25	510±130
D44A	95–280	PBS	25	5.3±2.4
D44V	95–280	PBS	25	8.4±2.4
D44V	95–280	PBS	4	1.5±0.47
D44V	95–280	PBS+NP40	25	1800±240
D44V	95–280	PBS+NP40	4	>4000
A46N	95–280	PBS	25	42±5.9
p28, p31	95–280	PBS	25	4.2±1.3

*PBS: 10 mM Na₂HPO₄, 2 mM KH₂PO₄, 137 mM NaCl, 2.7 mM KCl, pH 7.4, and 2 mM DTT; NaCl concentration is modified where indicated.