title: A membrane-bound HIPIP type center in the thermohalophile Rhodothermus marinus.
abstract: A HIPIP-type center was discovered in intact membranes of the thermohalophilic aerobe Rhodothermus marinus. In both the membrane-bound state and after detergent solubilization and partial purification, this center exhibits an almost axial EPR spectrum, with g-values at 2.13 and 2.03, similar to those of soluble HIPIP proteins isolated from purple bacteria. It has a high reduction potential, of 260 mV at pH 7.5. Rhodothermus HIPIP is involved in the main membrane-bound electron-transfer pathway, being reduced by NADH or succinate only in the presence of cyanide. The possible physiological function of this novel HIPIP-type center is discussed.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: M M
authors.initials: MM
authors.lastname: Pereira
authors.forename: A M
authors.initials: AM
authors.lastname: Antunes
authors.forename: O C
authors.initials: OC
authors.lastname: Nunes
authors.forename: M S
authors.initials: MS
authors.lastname: da Costa
authors.forename: M
authors.initials: M
authors.lastname: Teixeira
mesh_terms: D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D006088:Gram-Negative Aerobic Bacteria / Q000378:metabolism*; D006358:Hot Temperature; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D045322:Photosynthetic Reaction Center Complex Proteins
chemical_list: D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; C007943:high potential iron-sulfur protein