2hpy
From Proteopedia
Crystallographic model of lumirhodopsin
Structural highlights
Function[OPSD_BOVIN] Photoreceptor required for image-forming vision at low light intensity. Required for photoreceptor cell viability after birth. Light-induced isomerization of 11-cis to all-trans retinal triggers a conformational change leading to G-protein activation and release of all-trans retinal (By similarity).[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPhotoactivation of the visual rhodopsin, a prototypical G protein-coupled receptor (GPCR), involves efficient conversion of the intrinsic inverse-agonist 11-cis-retinal to the all-trans agonist. This event leads to the rearrangement of the heptahelical transmembrane bundle, which is thought to be shared by hundreds of GPCRs. To examine this activation mechanism, we determined the x-ray crystallographic model of the photoreaction intermediate of rhodopsin, lumirhodopsin, which represents the conformational state having the nearly complete all-trans agonist form of the retinal. A difference electron density map clearly indicated that the distorted all-trans-retinal in the precedent intermediate bathorhodopsin relaxes by dislocation of the beta-ionone ring in lumirhodopsin, along with significant peptide displacement in the middle of helix III, including approximately two helical turns. This local movement results in the breaking of the electrostatic interhelical restraints mediated by many of the conserved residues among rhodopsin-like GPCRs, with consequent acquisition of full activity. Local peptide movement in the photoreaction intermediate of rhodopsin.,Nakamichi H, Okada T Proc Natl Acad Sci U S A. 2006 Aug 22;103(34):12729-34. Epub 2006 Aug 14. PMID:16908857[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||||||
