Table 2.
Five distinct activation states represented by crystal structures of GPCRs (PDB codes and corresponding publications shown).
| Receptor | R Inactive State | R’ Inactive Agonist Bound | R’’ Active State | R* Active, with G& Mimic | R*G G protein Signaling |
|---|---|---|---|---|---|
| A2AAR | 3EML (45), 3REY, 3RFM, 3PWH (44), 3VGA, 3VG9 (111), 3UZA, 3UZC (112), 4EIY (57) | n/a | 3QAKa (19), 2YDOb, 2YDVb (20) | n/a | N/a |
| β 1 AR | 2VT4 (13), 2YCW, 2YCX, 2YCY, 2YCZ (42), 4AMI, 4AMJ (43a) | 2Y00, 2Y01, 2Y02, 2Y03, 2Y04 (43) | n/a | n/a | N/a |
| β 2 AR | 2RH1 (12, 27), 2R4R, 2R4S (113), 3D4S (40), 3KJ6 (103), 3NY8, 3NY9, 3NYA (41) | 3PDS (109) | n/a | 3P0Gc (22) | 3SN6d (21) |
| Rhodopsin | 1F88 (9), 1U19 (39)e | 2G87, 2HPY (38) | 3CAPf (15) | 3DQBfg (14), 2X72g (17), 3PQRg, 3PXOg (18) 4A4Mgb (18a) | N/a |
a
Stabilized by a conformationally selective agonist
b
Stabilized in activated state by point mutations
c
Complex with a nanobody mimicking Gα interactions
d
Complex with Gαβγ, additionally stabilized by a nanobody
e
Out of 15 dark state rhodopsin structures, only the first and the highest resolution structures are shown
f
Retinal-free opsin
g
Complex with C-terminal peptide Gα