My running summaries of the GPCR literature. The first three are more complete than the others. Literature references are included and whenever possible the positions have been translated into Joyce Baldwin's numbering system. Categories are fuzzy and not necessarily mutually exclusive. Caveat emptor and enjoy!GPCR numbering system correspondences
(1) constitutively activating point mutations
(2) suspected TM-TM contacts or distance constraints
(3) systematic site-directed labeling studies
(4) positions suspected important in the R->R* conformational change
(5) positions important in ligand efficacy and/or agonism vs. antagonism
(6) positions suspected important in folding, expression at the plasma membrane
(7) ligand-binding residues (this one is especially disorganized and incomplete)
(8) G protein-binding residues
(9) the opposite: GPCR-binding residues of G proteins
(10) alpha-beta-gamma specificity of receptor
(11) specificity amongst alpha, beta, and gamma