title: Dynamic structure of pharaonis phoborhodopsin (sensory rhodopsin II) and complex with a cognate truncated transducer as revealed by site-directed 13C solid-state NMR.
abstract: We have recorded (13)C nuclear magnetic resonance (NMR) spectra of [3-(13)C]Ala, [1-(13)C]Val-labeled pharaonis phoborhodopsin (ppR or sensory rhodopsin II) incorporated into egg PC (phosphatidylcholine) bilayer, by means of site-directed high-resolution solid-state NMR techniques. Seven (13)C NMR signals from transmembrane alpha-helices were resolved for [3-(13)C]Ala-ppR at almost the same positions as those of bacteriorhodopsin (bR), except for the suppressed peaks in the loop regions in spite of the presence of at least three Ala residues. In contrast, (13)C NMR signals from the loops were visible from [1-(13)C]Val-ppR but their peak positions of the transmembrane alpha-helices are not always the same between ppR and bR. The motional frequency of the loop regions in ppR was estimated as 10(5) Hz in view of the suppressed peaks from [3-(13)C]Ala-ppR due to interference with proton decoupling frequency. We found that conformation and dynamics of ppR were appreciably altered by complex formation with a cognate truncated transducer pHtr II (1-159). In particular, the C-terminal alpha-helix protruding from the membrane surface is involved in the complex formation and subsequent fluctuation frequency is reduced by one order of magnitude.
authors.affiliation: Department of Life Science, Graduate School of Science, Himeji Institute of Technology, Harima Science Garden City, Kouto 3-chome, Kamigori, Hyogo 678-1297, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Arakawa
authors.forename: Kazumi
authors.initials: K
authors.lastname: Shimono
authors.forename: Satoru
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Satoru
authors.initials: S
authors.lastname: Tuzi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sudo
authors.forename: Naoki
authors.initials: N
authors.lastname: Kamo
authors.forename: Hazime
authors.initials: H
authors.lastname: Saitô
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001436:Bacteriorhodopsins / Q000737:chemistry; D002247:Carbon Isotopes; D002338:Carotenoids / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D025602:Halorhodopsins; D008051:Lipid Bilayers / Q000737:chemistry; D046911:Macromolecular Substances; D016297:Mutagenesis, Site-Directed; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D010713:Phosphatidylcholines; D011487:Protein Conformation; D025603:Sensory Rhodopsins; D015398:Signal Transduction
chemical_list: D019843:Archaeal Proteins; D002247:Carbon Isotopes; D025602:Halorhodopsins; C434451:HtrII protein, Natronobacterium pharaonis; D008051:Lipid Bilayers; D046911:Macromolecular Substances; D010713:Phosphatidylcholines; D025603:Sensory Rhodopsins; C061508:sensory rhodopsin II protein, archaeal; D002338:Carotenoids; D001436:Bacteriorhodopsins