Table 5. Comparison of Distance of the Identified Interacting Residues^a from Contact Matrix Graphs of the Rhodopsin, CXCR4, and β₁AR Helices and the Crystal Rhodopsin Dimer (1N3M), CXCR4 Dimer (4GPO), and the β₁AR Dimer (3ODU).

receptor	helices	interacting residues	crystal structure distance (Å)	mean distance (Å) ± standard deviation
rhodopsin	TM1–TM2	F1271.47–L2182.44	15.28	14.2  ±  4.07
		M1191.39–D2242.50	9.01	10.32  ±  3.1
	TM4–TM5	F4184.48–L5215.51	12.07	9.18 ± 3.24
		T4194.49–L5215.51	14.77	8.13 ± 1.96
		G4154.45–F5255.55	16.44	7.5 ± 2.3
		H4114.41–Q5305.60	17.64	9.06 ± 3.34
CXCR4	TM5–TM5	F2015.40–V1985.37	7.37	15.55 ± 3.34
		F2015.40–Q2005.39	11.03	13.7 ± 1.46
		F2015.40–F2015.40	7.91	13.6 ± 2.89
		F2015.40–Q2025.41	8.72	14.93 ± 3.13
		F2015.40–I2045.43	12.14	13.11 ± 3.37
		F2015.40–M2055.44	10.6	12.6 ± 4.96
β1AR	TM1–TM1	W401.31–A421.33	12.21	15.28b
		W401.31–S451.36	12.41	17.5b
		W401.31–L461.37	13.84	18.3b
		M441.35–L461.37	9.8	13.46b
		A491.39–M481.38	8.86	5.39b
		L531.44–M481.38	12.19	5.01b
		L531.44–V511.40	10.75	4.9b
		L531.44–V521.41	11.13	5.2b
		L541.45–V511.40	13.9	5.09b
	TM4–TM5	K1594.43–Y2315.58	NDc	9.01 ± 2.22
		W1664.50–Y2275.62	NDc	7.9 ± 1.99

^aDistances are measured from backbone to backbone.

^bInteractions were detected in only one replica in the ensemble.

^cNot determined (ND): The distances between TM4 and TM5 could not be measured due to the orientation of the dimer in the 4GPO crystal structure, which is submitted showing the TM1–TM2 dimer interface.