Models of G-protein coupled receptors revised for family-wide compliance with experimental data. A new sequence...

The G-protein coupled receptors form a vast superfamily. The hydrophobic sequences of the transmembrane regions can be consistently and unambiguously aligned for nearly all, even distantly related, members owing to striking conserved patterns. As the fold is highly conserved in evolution, a model of the structure of the transmembrane helix bundle built for any individual receptor will thus be of family-wide relevance. Consequently the model must comply with key results experimentally obtained for other individual receptors. Meeting this demand can greatly reduce the uncertainties in modelling G-protein coupled receptors. This present communication shows how our recent template model based on the backbone structure of bacteriorhodopsin is revised according to that demand. Although it turns out to be in accordance with the experimental data in most of its parts, this revision suggests a sequence accommodation to helix G that is different from all other published models.