Publication Date:
2000-08-05
Description:
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 alpha 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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Palczewski, K -- Kumasaka, T -- Hori, T -- Behnke, C A -- Motoshima, H -- Fox, B A -- Le Trong, I -- Teller, D C -- Okada, T -- Stenkamp, R E -- Yamamoto, M -- Miyano, M -- EY09339/EY/NEI NIH HHS/ -- New York, N.Y. -- Science. 2000 Aug 4;289(5480):739-45.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA. palczews@u.washington.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10926528" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Motifs
;
Amino Acid Sequence
;
Animals
;
Cattle
;
Cell Membrane/chemistry
;
Crystallography, X-Ray
;
Heterotrimeric GTP-Binding Proteins/*metabolism
;
Hydrogen Bonding
;
Light
;
Molecular Sequence Data
;
Receptors, Cell Surface/*chemistry/metabolism
;
Retinaldehyde/chemistry/metabolism
;
Rhodopsin/*chemistry/metabolism
;
Schiff Bases
;
Stereoisomerism
;
Vision, Ocular
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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