All GPCR structures resolved at 3.1 Å or better, with small ions bound to 7TM domain

ReceptorPDB codeResolution Range, ÅIonSite
A2AAR4EIY, 5IU4, 5IU7, 5IU8, 5IUA, 5IUB, 5K2A, 5K2B, 5K2C, 5K2D, 5MZJ, 5MZP, 5N2R, 5NLX, 5NM2, 5NM4, 5OLG, 5OLH, 5OLV, 5OLZ, 5OM1, 5OM4, 5VRA1.7–2.8Na+D2.50, conserved, tight bindinga
DRD45WIV2.1Na+D2.50, conserved, tight binding
δ-OR4N6H, 4RWD1.8, 2.7Na+D2.50, conserved, tight binding
PAR13VW72.2Na+D2.50, conserved, tight binding
PAR25NDD2.8Na+D2.50, conserved, tight binding
CLTR16RZ4, 6RZ52.5–2.7Na+D2.50, conserved, tight binding
β1AR3ZPR, 4BVN, 5A8E2.1–2.7Na+D2.50, conserved, tight binding
β1AR2VT4, 2Y00, 2Y02, 2Y03, 2Y04, 2YCW, 3ZPQ, 3ZPR, 4AMJ, 4BVN, 5A8E, 6H7J, 6H7K, 6H7L, 6H7M, 6H7N, 6H7O2.1–3.1Na+ECL2, backbone, tight binding
β2AR4LDE, 4LDL2.8, 3.1Na+ECL2, backbone, tight binding
SMO, class F5L7D3.2Na+Loose binding
A2AAR5OM12.1ClHelices VI and VIII (H230, R293), loose binding
PAR13VW72.2Cl-Helices II, III, VI, (K135, R200, K307), loose binding
Rhodopsin1GZM, 1F88, 1U19, 1L9H, 1HZX, 2HPY, 2G87, 2PED, 3C9L, 3OAX2.2–3.0Zn2+Additive in crystallization protocols. Loose binding in multiple sites.
PAF5ZKQ2.9Zn2+Helices I, VI, VII (H4, H8, E259, H268), tight binding
SMO, class F4QIM, 4N4W2.6, 2.8Zn2+Loose binding
M2R5YC82.5Hg2+Used as anomalous scatterers for phasing. Loose binding in multiple sites.
Rhodopsin1U19, 1L9H, 1HZX, 1F88, 2PED, 2G87, 2HPY, 3OAX2.2–3.0Hg2+
5HT2B6DRY, 6DRZ2.9, 3.1PO43−Loose binding
DRD45WIU, 5WIV2, 2.1PO43−ICL2 and Helix III, tight binding
H1R3RZE3.1PO43−7TM bundle, ECL, (K179, K191, Y431, H450), tight binding
μ-OR5C1M2.1PO43−Loose binding
A2AAR3EML2.6SO42−Loose binding
CB15U092.6SO42−Loose binding
CCR25T1A2.8SO42−Helix VIII, ICL1, tight binding
ETB15X93, 5GLI2.2, 2.5SO42−Inside 7TM, intracellular (R199, R208, K210), tight binding, commonb
PD26D27, 6D262.7, 2.8SO42−Inside 7TM, intracellular (R143, R2243), tight binding, commonb
+ Other loose binding sites
EP36M9T2.5SO42−Loose binding
Rhodopsin3PQR, 4J4Q, 4PXF, 5DYS, 5EN0, 5TE32.3–2.9SO42−Loose binding
β2AR2RH1, 5D5A2.4, 2.5SO42−Inside 7TM, intracellular (T68, R131), tight binding, commonb
VI, VII (K270, K273, R328), tight binding
μ-OR4DKL2.8SO42−Inside 7TM, intracellular (T103, R179), tight binding, commonb
Other six loose binding sites
  • a Directly coordinated by two or more ionic interactions with charged residues.

  • b SO42− bound at a common intracellular site in several receptors.