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Thiosulfate reduction in Salmonella enterica is driven by the proton motive force.
Stoffels, Laura; Krehenbrink, Martin; Berks, Ben C; Unden, Gottfried.
Afiliación
  • Stoffels L; Institute for Microbiology and Wine Research, Johannes Gutenberg-University of Mainz, Mainz, Germany.
J Bacteriol ; 194(2): 475-85, 2012 Jan.
Article en En | MEDLINE | ID: mdl-22081391
ABSTRACT
Thiosulfate respiration in Salmonella enterica serovar Typhimurium is catalyzed by the membrane-bound enzyme thiosulfate reductase. Experiments with quinone biosynthesis mutants show that menaquinol is the sole electron donor to thiosulfate reductase. However, the reduction of thiosulfate by menaquinol is highly endergonic under standard conditions (ΔE°' = -328 mV). Thiosulfate reductase activity was found to depend on the proton motive force (PMF) across the cytoplasmic membrane. A structural model for thiosulfate reductase suggests that the PMF drives endergonic electron flow within the enzyme by a reverse loop mechanism. Thiosulfate reductase was able to catalyze the combined oxidation of sulfide and sulfite to thiosulfate in a reverse of the physiological reaction. In contrast to the forward reaction the exergonic thiosulfate-forming reaction was PMF independent. Electron transfer from formate to thiosulfate in whole cells occurs predominantly by intraspecies hydrogen transfer.
Asunto(s)

Texto completo: 1 Base de datos: MEDLINE Asunto principal: Tiosulfatos / Fuerza Protón-Motriz / Salmonella enterica Idioma: En Revista: J Bacteriol Año: 2012 Tipo del documento: Article

Texto completo: 1 Base de datos: MEDLINE Asunto principal: Tiosulfatos / Fuerza Protón-Motriz / Salmonella enterica Idioma: En Revista: J Bacteriol Año: 2012 Tipo del documento: Article