Table 2.

Experimental Means and Widths of Distance Distributions between Pairs of Spin-Labels in HIV-RT from DEER^a

construct	mean distance ± width at half-height (Å)
	unliganded	with DNA	with NNRTIs
C38/C280	56 ± 3b	56 ± 4	46 ± 6
C38/A304C	83 ± 9 (56%)c	83 ± 8	56 ± 6
	42 ± 8 (44%)c
W24C/C280	22 ± 5 (56%)c	46 ± 5	45 ± 4
	42 ± 14 (44%)c
T39C/E308C	53 ± 3b	68 ± 3	67 ± 3

^aObtained from a two-Gaussian fit using the program DD.²⁰ No significant differences are found using three-Gaussian fits or validated Tikhonov regularization²² (see Tables S2–S5).

^bThe P(r) distributions for the C38-R1/C280-R1 and T39C-R1/E308C-R1 constructs contain an additional broad component with widths of 13 and 20 Å, respectively, and corresponding mean distances of 56 and 58 Å, respectively, very close to the mean distance of the narrow component (see the Experimental section of the Supporting Information).

^cValues in parentheses refer to conformer populations.