Active State-like Conformational Elements in the β2-AR and a Photoactivated Intermediate of Rhodopsin Identified by Dynamic Properties of GPCRs

Abstract

G-Protein-coupled receptors (GPCRs) adopt various functionally relevant conformational states in cell signaling processes. Recently determined crystal structures of rhodopsin and the β₂-adrenergic receptor (β₂-AR) offer insight into previously uncharacterized active conformations, but the molecular states of these GPCRs are likely to contain both inactive and active-like conformational elements. We have identified conformational rearrangements in the dynamics of the TM7−HX8 segment that relate to the properties of the conserved NPxxY(x)5,6F motif and show that they can be used to identify active state-like conformational elements in the corresponding regions of the new structures of rhodopsin and the β₂-AR.