title: Sensory rhodopsin II and bacteriorhodopsin: light activated helix F movement.
abstract: EPR spectroscopy in combination with site directed spin labeling (SDSL) has become a valuable tool for structural investigations as well as for kinetic studies on proteins. This method has been especially useful for membrane proteins in yielding structural and functional data. This information is not easily available from other techniques, like, e.g., X-ray crystallography or electron microscopy. In the first part of this two part review, the topology of the sensory rhodopsin II/transducer complex (NpSRII/NpHtrII) derived from EPR constraints is compared to that obtained from X-ray crystallography. In the second part, the helix F movement observed for both sensory rhodopsin and bacteriorhodopsin is evaluated and discussed in order to establish a common mechanism after photoreceptor activation.
authors.affiliation: Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Str. 11, D-44227 Dortmund, Germany.
authors.forename: Johann P
authors.initials: JP
authors.lastname: Klare
authors.forename: Enrica
authors.initials: E
authors.lastname: Bordignon
authors.forename: Martin
authors.initials: M
authors.lastname: Engelhard
authors.forename: Heinz-Jürgen
authors.initials: HJ
authors.lastname: Steinhoff
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry* / Q000528:radiation effects*; D004578:Electron Spin Resonance Spectroscopy; D025602:Halorhodopsins / Q000737:chemistry* / Q000528:radiation effects*; D008027:Light; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000528:radiation effects; D025603:Sensory Rhodopsins / Q000737:chemistry* / Q000528:radiation effects*
chemical_list: D025602:Halorhodopsins; D011994:Recombinant Proteins; D025603:Sensory Rhodopsins; C061508:sensory rhodopsin II protein, archaeal; D001436:Bacteriorhodopsins