title: Identification of chromatophore membrane protein complexes formed under different nitrogen availability conditions in Rhodospirillum rubrum.
abstract: The chromatophore membrane of the photosynthetic diazotroph Rhodospirillum rubrum is of vital importance for a number of central processes, including nitrogen fixation. Using a novel amphiphile, we have identified protein complexes present under different nitrogen availability conditions by the use of two-dimensional Blue Native/SDS-PAGE and NSI-LC-LTQ-Orbitrap mass spectrometry. We have identified several membrane protein complexes, including components of the ATP synthase, reaction center, light harvesting, and NADH dehydrogenase complexes. Additionally, we have identified differentially expressed proteins, such as subunits of the succinate dehydrogenase complex and other TCA cycle enzymes that are usually found in the cytosol, thus hinting at a possible association to the membrane in response to nitrogen deficiency. We propose a redox sensing mechanism that can influence the membrane subproteome in response to nitrogen availability.
authors: Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
authors: Tiago Toscano
authors: TT
authors: Selao
authors: Rui
authors: R
authors: Branca
authors: Pil Seok
authors: PS
authors: Chae
authors: Janne
authors: J
authors: Lehtiö
authors: Samuel H
authors: SH
authors: Gellman
authors: Søren G F
authors: SG
authors: Rasmussen
authors: Stefan
authors: S
authors: Nordlund
authors: Agneta
authors: A
authors: Norén
mesh_terms: D025181:ATP Synthetase Complexes / Q000737:chemistry / Q000378:metabolism; D000643:Ammonium Chloride / Q000378:metabolism; D020130:Bacterial Chromatophores / Q000737:chemistry / Q000378:metabolism*; D002952:Citric Acid Cycle; D042967:Electron Transport Complex I / Q000737:chemistry / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D005420:Flavoproteins / Q000737:chemistry / Q000378:metabolism; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D009586:Nitrogen Fixation; D012247:Rhodospirillum rubrum / Q000254:growth & development / Q000378:metabolism*; D013347:Subcellular Fractions / Q000737:chemistry
chemical_list: D005420:Flavoproteins; D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D000643:Ammonium Chloride; D025181:ATP Synthetase Complexes; D042967:Electron Transport Complex I; D009584:Nitrogen