Research Article

Crystal Structure of Rhodopsin: A G Protein-Coupled Receptor

+ See all authors and affiliations

Science  04 Aug 2000:
Vol. 289, Issue 5480, pp. 739-745
DOI: 10.1126/science.289.5480.739

You are currently viewing the abstract.

View Full Text

Abstract

Heterotrimeric guanine nucleotide–binding protein (G protein)–coupled receptors (GPCRs) respond to a variety of different external stimuli and activate G proteins. GPCRs share many structural features, including a bundle of seven transmembrane α helices connected by six loops of varying lengths. We determined the structure of rhodopsin from diffraction data extending to 2.8 angstroms resolution. The highly organized structure in the extracellular region, including a conserved disulfide bridge, forms a basis for the arrangement of the seven-helix transmembrane motif. The ground-state chromophore, 11-cis-retinal, holds the transmembrane region of the protein in the inactive conformation. Interactions of the chromophore with a cluster of key residues determine the wavelength of the maximum absorption. Changes in these interactions among rhodopsins facilitate color discrimination. Identification of a set of residues that mediate interactions between the transmembrane helices and the cytoplasmic surface, where G-protein activation occurs, also suggests a possible structural change upon photoactivation.

  • * To whom correspondence should be addressed. E-mail: miyano{at}spring8.or.jp (M.M.); palczews{at}u.washington.edu(K.P.); stenkamp{at}u.washington.edu (R.E.S.).

View Full Text