Table 1.

RNA binding parameters of AUF1 p45 and its variants.

	AU/GU-rich RNA			random RNA
Protein	KD (nM)a	KD ratiob	ΔΔG (kJ/mol)c	KD (nM)a	KD ratiob	ΔΔG (kJ/mol)c
AUF1 p45 WT	1.6 ± 0.5	1	0	157 ± 24	1	0
AUF1 p45 RRM1mut	25 ± 3.2	16	6.8	1260 ± 217	8	5.1
AUF1 p45 RRM2mut	24 ± 3.4	15	6.7	414 ± 49	2.6	2.4
AUF1 p45 RRM1 + 2mut	1040 ± 290	650	15.9	4170 ± 909	27	8.9
AUF1 p45 RGG5K	4.3 ± 1.0	2.7	2.4	314 ± 50	2	1.7
AUF1 p45 RGG5A	24 ± 3.1	15	6.7	2840 ± 191	18	7.1

^aDissociation constants and standard deviations derived from at least three measurements.

^bK_D ratio was calculated to compare binding of wildtype (WT) vs protein variant.

^cThe Gibbs free energy difference between a WT-RNA complex and a variant-RNA complex was calculated as follows: ΔΔG = -RT ln(K_D WT/K_D variant).