Table 1. Equilibrium denaturation parameters for wild type and mutants of TAPLRR.

The m-values and midpoints of unfolding ([U]^50%) listed are those obtained by fitting the individual denaturation curves to a two-state equation. The weighted-average of the m-values of wild type and those mutants with long pre-transition baselines in the denaturation curves (<m> = 2.66 ± 0.14) was then used to refit the denaturation curves. The midpoints of unfolding obtained from these fits were used to calculate the changes in the free energy of unfolding upon mutation, $\Delta \Delta G_{D-N}^{H_{2}O}=<m>({{\left[U\right]}^{50\%}}_{\text{wild type}}-{{\left[U\right]}^{50\%}}_{\text{mutant}})$. The errors are the standard deviations from the fits of the data.

Protein	Location	Location of interacting residues	m-value (kcal mol−1 M−1)	[D]50% (M)	$\Delta \Delta G_{\mathrm{U}-\mathrm{N}}^{{\mathrm{H}}_2\mathrm{O}}$ (kcal mol−1)
WT			3.21 ± 0.25	1.64 ± 0.02	-
L212V	α1 cap	LRR1	-	1.08 ± 0.11*	1.38 ± 0.31
M216L	α1 cap	LRR1	2.56 ± 0.14	1.70 ± 0.02	−0.27 ± 0.10
L238I	α2 cap	Cap	3.44 ± 0.44	1.51 ± 0.03	0.35 ± 0.13
I264V	α3-β2 strand LRR1	Cap	3.40 ± 0.21	1.41 ± 0.02	0.64 ± 0.10
L267I	α3-β2 strand LRR1	Cap LRR2	2.27 ± 0.23	1.52 ± 0.05	0.11 ± 0.11
V287A	α4 LRR2	LRR3	2.66 ± 0.24	1.54 ± 0.03	0.16 ± 0.11
L293I	α4-β3 strand LRR2	LRR1 LRR3	2.92 ± 0.23	1.33 ± 0.03	0.80 ± 0.12
L293V	α4-β3 strand LRR2	LRR1 LRR3	-	1.07 ± 0.06*	1.41 ± 0.19
L315A	α5-β4 strand LRR3	LRR2 LRR4	-	0.98 ± 0.09*	1.65 ± 0.27
L317I	α5-β4 strand LRR3	LRR2 LRR4	2.52 ± 0.22	1.26 ± 0.04	0.85 ± 0.12
S339A	α6 LRR4	LRR4	2.85 ± 0.55	1.73 ± 0.06	−0.32 ± 0.18
L348I	α6-β5 strand LRR4	LRR3 C-terminus	2.88 ± 0.41	1.42 ± 0.05	0.53 ± 0.14
L349I	β5 LRR4	LRR3	2.38 ± 0.30	1.60 ± 0.05	−0.05 ± 0.13

^*The pre-transition baseline was absent or very short for three highly destabilising mutations, L212V, L293V and L315A, resulting in poor fits of the data. Therefore, for these mutants the values of [U]^50% listed are those obtained by fitting the denaturation curves with the m-value fixed at <m>.