Table 2.

Melting temperatures (T_m) in the presence and absence of ATP.^a

Variant	ATP	Tm1b (°C)	Tm2b (°C)
WT	0	44.4 ± 0.2	None
F86L	0	30.9 ± 0.9	55.1 ± 0.9
E258A	0	(47.8 ± 1.8)c	(N.A.)c
WT	2 mM	N.A.	59.4 ± 0.9
F86L	2 mM	N.A.	54.7 ± 0.1
E258A	2 mM	N.A.	56.5 ± 0.7

^aT_m values were estimated from curve fits of thermofluor data in Figure 4, as described in Materials and Methods. N.A. – not applicable.

^bThe low temperature transition observed with WT RAD51 in the absence of ATP is referred to as T_m1, and the high-temperature transition observed in the presence of ATP is referred to as T_m2. The low and high temperature transitions observed with RAD51 variants under various conditions are categorized as T_m1 or T_m2 based on an arbitrary cutoff of 50°C.

^cThe melting curve for E258A in the absence of ATP likely includes two transitions, but these were poorly resolved (Fig. 4). The reported value of T_m1 represents the overall midpoint of the melting curve, which may be considered a composite or average of the different transitions.