The binding sites for dopamine receptors are contained in a binding crevice formed by the transmembrane helices 3, 5, 6 and 7. The energetically most important interaction is most likely a salt bridge between the charged amine of ligands and the carboxylated side chain of Asp114 in TM 3.
Click on D-114 in this snake-like view:
http://www.gpcr.org/7tm/seq/diagrams_MuteXt/DRD2_HUMAN-rbdg.htmland you will get details of contacts between ligands and DRD2:
http://www.gpcr.org/7tm/mutation/SameResidue_Xtext/DRD2_HUMAN_114_Xtext.html The photochromophore of rhodopsin and the opsins, 11-cis-retinal, is unique among the endogenous ligands for GPCRs in that it is covalently attached to the receptor within a binding crevice formed by the TM helices
I have found these review very useful to understand the molecular mechanisms of GPCR activation:
Gether U, Endocrine Reviews 21 (1): 90-113, 2000
http://edrv.endojournals.org/cgi/content/full/21/1/90Ji T. H., J Biol Chem, Vol. 273, Issue 28, 17299-17302, 1998
http://www.jbc.org/cgi/content/full/273/28/17299?ijkey=279ffa21087f26af10709af810485e07fae32c22&keytype2=tf_ipsecsha| SRep said: |
| I've been trying to locate the residues involved in ligand binding for either rhodopsin or D2 dopamine receptor-- is there any place that I can just find a list or something?? pubmed hasnt helped very much so far |