MODELS OF G-PROTEIN COUPLED RECEPTORS REVISED FOR FAMILY-WIDE COMPLIANCE WITH EXPERIMENTAL-DATA - A NEW SEQUENCE ACCOMMODATION SUGGESTED FOR HELIX-G

The G-protein coupled receptors form a vast superfamily. The hydrophob ic sequences of the transmembrane regions can be consistently and unam biguously aligned for nearly all, even distantly related, members owin g to striking conserved patterns. As the fold is highly conserved in e volution, a model of the structure of the transmembrane helix bundle b uilt for any individual receptor will thus be of family-wide relevance . Consequently the model must comply with key results experimentally o btained for other individual receptors. Meeting this demand can greatl y reduce the uncertainties in modelling G-protein coupled receptors. T his present communication shows how our recent template model based on the backbone structure of bacteriorhodopsin is revised according to t hat demand. Although it turns out to be in accordance with the experim ental data in most of its parts, this revision suggests a sequence acc ommodation to helix G that is different from all other published model s.