title: Physiological proteomics of the uncultured endosymbiont of Riftia pachyptila.
abstract: The bacterial endosymbiont of the deep-sea tube worm Riftia pachyptila has never been successfully cultivated outside its host. In the absence of cultivation data, we have taken a proteomic approach based on the metagenome sequence to study the metabolism of this peculiar microorganism in detail. As one result, we found that three major sulfide oxidation proteins constitute approximately 12% of the total cytosolic proteome, which highlights the essential role of these enzymes for the symbiont's energy metabolism. Unexpectedly, the symbiont uses the reductive tricarboxylic acid cycle in addition to the previously identified Calvin cycle for CO2 fixation.
authors.affiliation: Institute of Marine Biotechnology, Walther-Rathenau-Strasse 49, D-17489 Greifswald, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Markert
authors.forename: Cordelia
authors.initials: C
authors.lastname: Arndt
authors.forename: Horst
authors.initials: H
authors.lastname: Felbeck
authors.forename: Dörte
authors.initials: D
authors.lastname: Becher
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Sievert
authors.forename: Michael
authors.initials: M
authors.lastname: Hügler
authors.forename: Dirk
authors.initials: D
authors.lastname: Albrecht
authors.forename: Julie
authors.initials: J
authors.lastname: Robidart
authors.forename: Shellie
authors.initials: S
authors.lastname: Bench
authors.forename: Robert A
authors.initials: RA
authors.lastname: Feldman
authors.forename: Michael
authors.initials: M
authors.lastname: Hecker
authors.forename: Thomas
authors.initials: T
authors.lastname: Schweder
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D052837:Chemoautotrophic Growth; D002952:Citric Acid Cycle; D003600:Cytosol / Q000378:metabolism; D017753:Ecosystem; D004734:Energy Metabolism; D020563:Gammaproteobacteria / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D016680:Genome, Bacterial; D006862:Hydrogen Sulfide / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D053858:Metabolic Networks and Pathways; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010140:Pacific Ocean; D011077:Polychaeta / Q000382:microbiology*; D020543:Proteome; D040901:Proteomics; D013455:Sulfur / Q000378:metabolism; D013559:Symbiosis; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D020543:Proteome; D002245:Carbon Dioxide; D013455:Sulfur; D002244:Carbon; D006862:Hydrogen Sulfide