Structural waters define a functional channel mediating activation of the GPCR, rhodopsin.

ABSTRACT: Structural water molecules may act as prosthetic groups indispensable for proper protein function. In the case of allosteric activation of G protein-coupled receptors (GPCRs), water likely imparts structural plasticity required for agonist-induced signal transmission. Inspection of structures of GPCR superfamily members reveals the presence of conserved embedded water molecules likely important to GPCR function. Coupling radiolytic hydroxyl radical labeling with rapid H(2)O(18) solvent mixing, we observed no exchange of these structural waters with bulk solvent in either ground state or for the Meta II or opsin states. However, the radiolysis approach permitted labeling of selected side chain residues within the transmembrane helices and revealed activation-induced changes in local structu

SUBMITTER: Angel TE 

PROVIDER: S-EPMC2732891 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature