Sulfide oxidation in the phototrophic sulfur bacterium Chromatium vinosum

verfasst von: Michael Reinartz, Jürgen Tschäpe, Thomas Brüser, Hans G. Trüper, Christiane Dahl
Abstract: Sulfide oxidation in the phototrophic purple sulfur bacterium Chromatium vinosum D (DSMZ 180(T)) was studied by insertional inactivation of the fccAB genes, which encode flavocytochrome c, a protein that exhibits sulfide dehydrogenase activity in vitro. Flavocytochrome c is located in the periplasmic space as shown by a PhoA fusion to the signal peptide of the hemoprotein subunit. The genotype of the flavocytochrome-c-deficient Chr. vinosum strain FDI was verified by Southern hybridization and PCR, and the absence of flavocytochrome c in the mutant was proven at the protein level. The oxidation of thiosulfate and intracellular sulfur by the flavocytochrome- c-deficient mutant was comparable to that of the wild-type. Disruption of the fccAB genes did not have any significant effect on the sulfide-oxidizing ability of the cells, showing that flavocytochrome c is not essential for oxidation of sulfide to intracellular sulfur and indicating the presence of a distinct sulfide-oxidizing system. In accordance with these results, Chr. vinosum extracts catalyzed electron transfer from sulfide to externally added duroquinone, indicating the presence of the enzyme sulfide:quinone oxidoreductase (EC 1.8.5.-). Further investigations showed that the sulfide:quinone oxidoreductase activity was sensitive to heat and to quinone analogue inhibitors. The enzyme is strictly membrane-bound and is constitutively expressed. The presence of sulfide:quinone oxidoreductase points to a connection of sulfide oxidation to the membrane electron transport system at the level of the quinone pool in Chr. vinosum.
Externe Organisation(en): Rheinische Friedrich-Wilhelms-Universität Bonn
Typ: Artikel
Journal: Archives of Microbiology
Band: 170
Seiten: 59-68
Anzahl der Seiten: 10
ISSN: 0302-8933
Publikationsdatum: 1998
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Mikrobiologie, Biochemie, Molekularbiologie, Genetik
Elektronische Version(en): https://doi.org/10.1007/s002030050615 (Zugang: Unbekannt)

BibTeX

@article{82e374daf28848eabdad6336fc9656b1,
title = "Sulfide oxidation in the phototrophic sulfur bacterium Chromatium vinosum",
abstract = "Sulfide oxidation in the phototrophic purple sulfur bacterium Chromatium vinosum D (DSMZ 180(T)) was studied by insertional inactivation of the fccAB genes, which encode flavocytochrome c, a protein that exhibits sulfide dehydrogenase activity in vitro. Flavocytochrome c is located in the periplasmic space as shown by a PhoA fusion to the signal peptide of the hemoprotein subunit. The genotype of the flavocytochrome-c-deficient Chr. vinosum strain FDI was verified by Southern hybridization and PCR, and the absence of flavocytochrome c in the mutant was proven at the protein level. The oxidation of thiosulfate and intracellular sulfur by the flavocytochrome- c-deficient mutant was comparable to that of the wild-type. Disruption of the fccAB genes did not have any significant effect on the sulfide-oxidizing ability of the cells, showing that flavocytochrome c is not essential for oxidation of sulfide to intracellular sulfur and indicating the presence of a distinct sulfide-oxidizing system. In accordance with these results, Chr. vinosum extracts catalyzed electron transfer from sulfide to externally added duroquinone, indicating the presence of the enzyme sulfide:quinone oxidoreductase (EC 1.8.5.-). Further investigations showed that the sulfide:quinone oxidoreductase activity was sensitive to heat and to quinone analogue inhibitors. The enzyme is strictly membrane-bound and is constitutively expressed. The presence of sulfide:quinone oxidoreductase points to a connection of sulfide oxidation to the membrane electron transport system at the level of the quinone pool in Chr. vinosum.",
keywords = "Chromatium vinosum, Flavocytochrome c Sulfide:quinone oxidoreductase, Interposon mutagenesis phoA fusion, Sulfide oxidation Phototrophic sulfur bacteria",
author = "Michael Reinartz and J{\"u}rgen Tsch{\"a}pe and Thomas Br{\"u}ser and Tr{\"u}per, {Hans G.} and Christiane Dahl",
note = "Funding Information: Acknowledgements This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie. We thank R. Steudel for his suggestions concerning the mechanism of sulfur globule formation, and M. Ehrmann for plasmid pSWFII. H. Reichenbach is acknowledged for his kind gift of myxothiazol. Copyright: Copyright 2007 Elsevier B.V., All rights reserved.",
year = "1998",
doi = "10.1007/s002030050615",
language = "English",
volume = "170",
pages = "59--68",
journal = "Archives of Microbiology",
issn = "0302-8933",
publisher = "Springer Verlag",
number = "1",
}