title: Symmetry matters for the electronic structure of core complexes from Rhodopseudomonas palustris and Rhodobacter sphaeroides PufX-.
abstract: Low-temperature (1.4 K), single-molecule fluorescence-excitation spectra have been recorded for individual reaction center-light-harvesting 1 complexes from Rhodopseudomonas palustris and the PufX(-) strain of Rhodobacter sphaeroides. More than 80% of the complexes from Rb. sphaeroides show only broad absorption bands, whereas nearly all of the complexes from Rps. palustris also have a narrow line at the low-energy end of their spectrum. We describe how the presence of this narrow feature indicates the presence of a gap in the electronic structure of the light-harvesting 1 complex from Rps. palustris, which provides strong support for the physical gap that was previously modeled in its x-ray crystal structure.
authors.affiliation: Experimental Physics IV and Bayreuth Institute of Macromolecular Research, University of Bayreuth, D-95440 Bayreuth, Germany.
authors.forename: M F
authors.initials: MF
authors.lastname: Richter
authors.forename: J
authors.initials: J
authors.lastname: Baier
authors.forename: T
authors.initials: T
authors.lastname: Prem
authors.forename: S
authors.initials: S
authors.lastname: Oellerich
authors.forename: F
authors.initials: F
authors.lastname: Francia
authors.forename: G
authors.initials: G
authors.lastname: Venturoli
authors.forename: D
authors.initials: D
authors.lastname: Oesterhelt
authors.forename: J
authors.initials: J
authors.lastname: Southall
authors.forename: R J
authors.initials: RJ
authors.lastname: Cogdell
authors.forename: J
authors.initials: J
authors.lastname: Köhler
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry*; D012242:Rhodobacter sphaeroides / Q000737:chemistry*; D012241:Rhodopseudomonas / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D001426:Bacterial Proteins; D045342:Light-Harvesting Protein Complexes; C088749:PufX protein, Rhodobacter