SUPPLEMENTAL MATERIAL

TABLE S1a Hydrogen bonds formed by residues between TMs of D1 receptor

Donor / Acceptor / Distance
(Å)
Residue / Group / Group / Residue
T1.46 / OH / OH / S7.46 / 2.77
N1.50 / NH / OH / S7.46 / 3.06
S2.45 / OH / O1 / N3.42 / 3.11
N7.49 / NH / O1 / D2.50 / 3.18
W4.50 / NH / OH / S2.45 / 2.95
Y5.38 / OH / O=C< / I4.56 / 2.63
W7.40 / NH / O1 / E2.65 / 3.05
N7.45 / NH / O1 / D3.32 / 3.32
R3.50 / N1H / O1 / E6.30 / 3.29
R3.50 / N2H / O=C< / E6.30 / 3.26
R3.50 / N2H / O1 / E6.30 / 3.10
K6.32 / NH / O=C< / D7.58 / 2.87
C6.47 / SH / O=C< / F7.41 / 3.05

TABLE S1b Hydrogen bonds formed by residues between TMs of D2 receptor

Donor / Acceptor / Distance
(Å)
Residue / Group / Group / Residue
N2.40 / NH / OH / Y7.53 / 2.98
N7.49 / NH / O1 / D2.50 / 3.19
W7.40 / NH / O1 / E2. 65 / 3.01
S4.57 / OH / SH / M3.34 / 3.28
S3.47 / OH / OH / T5.54 / 3.11
T5.54 / OH / OH / S3.47 / 3.11
R3.50 / NH / OH / T6.34 / 2.91
R3.50 / N1H / O1 / E6.30 / 3.32
R3.50 / N2H / O1 / E6.30 / 3.05
R3.50 / N2H / OH / T6.34 / 3.22
C6.47 / SH / O=C< / L7.41 / 3.05

Fig. S1 Schematic flowchart of the modeling and simulation.

Fig.S2Sequence alignments of Rhodopsin (1F88) with the D1 and D2 receptor models generated by ClustalW and visualized by ESPript. A red box indicates strict identity, and a yellow box indicates similarity within a group (Sequence identity is 21.8%, similarity is 47.8% in the TM region between Rhodopsin and D1; Sequence identity is 26.1%, similarity is 54.4% in the TM region between Rhodopsin and D2; and the identity in the TM region between D1 and D2 is 44.5%, the similarity is 66.4%). The most conserved residues X.50 for each TM are marked by a black star under the sequences. The seven transmembrane helices (TM), extracellular loops (EL) and intracellular loops (IL) were marked above the sequences.

Fig.S3Ramachandran plots of the D1 and D2 receptor models. The different colored areas indicate “disallowed” (white), “generously allowed” (light yellow), “additional allowed” (yellow), and “most favored” (red) regions.

Fig. S4 Cartoon representation of the optimized 3D models for D1 and D2 receptors. There are three intra-molecular hydrophobic interaction clusters for both D1 and D2: cluster 1 in red among TMs V, VI and VII; cluster 2 in blue color between TMs II and IV; and cluster 3 in purple between TMs III and V. (A) Side view of the D1 receptor model; (B) Top view from the extracellular side of the D1 receptor (without loops for clear visualization of the TMs); (C) Side view of the D2 receptor model; (D) Similar top view from the extracellular side for the D2 receptor model.