Table 3.

Thermodynamic parameters of RGG/RG motif variants in RNA annealing.

Protein	kcat/KM (106 s−1 M−1)a	ΔΔG≠ (kJ/mol)b
AUF1 p45 WT	4.61	0
AUF1 p45 RGG5K	1.84	2.3
AUF1 p45 RGG5A	0.04	11.6
AUF1 p45 R272A	1.78	2.3
AUF1 p45 R278A	2.11	1.9
AUF1 p45 R280A	1.52	2.7
AUF1 p45 R282A	2.53	1.5
AUF1 p45 R345A	2.30	1.7

^aThe catalytic efficiency k_cat/K_M was determined from the slope of the k_obs values plotted as a function of the protein concentration.

^bThe RNA annealing free energy difference ΔΔG^≠ between the WT and the variants was calculated using Equation (7) (see materials and methods).