title: Effects of iron limitation on the respiratory chain and the membrane cytochrome pattern of the Euryarchaeon Halobacterium salinarum.
abstract: The effects of iron limitation on the electron transport chain of the extremely halophilic Euryarchaeon Halobacterium salinarum were analyzed. When iron was growth-limiting, the respiratory rates as well as the inhibition pattern of the membranes were significantly different from membranes of iron replete cells. Changes in the availability of iron cause the formation of different respiratory pathways including different entry sites for electrons, different terminal oxidases of the respiratory chain, and drastic changes of the cytochrome composition and of the relative amounts of cytochromes. Under iron-limiting conditions, mainly low-potential cytochromes were measured. EPR spectroscopic studies revealed that the amount of proteins containing iron-sulfur clusters is reduced in membranes under iron-limiting growth conditions. Taken together, our results strongly suggest for the first time an important role of iron supply for the bioenergetics of an Archaeon.
authors.affiliation: Institut für Biochemie, Universität zu Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Hubmacher
authors.forename: Berthold F
authors.initials: BF
authors.lastname: Matzanke
authors.forename: Stefan
authors.initials: S
authors.lastname: Anemüller
mesh_terms: D000968:Antimycin A / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology; D002462:Cell Membrane / Q000737:chemistry; D003580:Cytochromes / Q000032:analysis / Q000378:metabolism*; D003600:Cytosol / Q000737:chemistry; D004227:Dithionite / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport / Q000187:drug effects / Q000502:physiology*; D019617:Halobacterium salinarum / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D007501:Iron / Q000378:metabolism / Q000494:pharmacology; D000090463:Iron Deficiencies; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D008954:Models, Biological; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D011190:Potassium Cyanide / Q000494:pharmacology; D015363:Quinolones / Q000494:pharmacology; D013053:Spectrophotometry; D019802:Succinic Acid / Q000378:metabolism / Q000494:pharmacology
chemical_list: D003580:Cytochromes; D007506:Iron-Sulfur Proteins; D015363:Quinolones; D009243:NAD; C052097:aurachin D; D004227:Dithionite; D000968:Antimycin A; D019802:Succinic Acid; D007501:Iron; D011190:Potassium Cyanide; D001205:Ascorbic Acid