TABLE 2.

Summary of FRET values and calculated distances between D-FKBP and His tags in the RyR1 central domain

Donor Positiona	FRET (observed)b	Nc	Apparent D/A distanced
His2341
14	0.47 ± 0.06	30	61 (58–63)
32	0.41 ± 0.12	9	63 (58–69)
44	0.52 ± 0.09	46	58 (55–62)
49	0.46 ± 0.13	30	61 (56–67)
85	0.45 ± 0.12	16	61 (56–67)
His2777
14	0.23 ± 0.06	53	73 (69–77)
32	0.30 ± 0.08	28	68 (64–73)
44	0.25 ± 0.07	62	71 (67–77)
49	0.30 ± 0.07	51	69 (65–72)
85	0.27 ± 0.10	37	70 (64–76)

^a Amino acid residue attachment site of AF488 on FKBP.

^b Observed FRET efficiency (mean ± S.D.).

^c Number of measurements.

^d Average and range (in parentheses) of donor-acceptor distances (in Å) calculated from the mean and S.D. of the measured FRET efficiencies.