Regulation of a novel Acidithiobacillus caldus gene cluster involved in metabolism of reduced inorganic sulfur compounds

Rzhepishevska, OI; Valdés J.; Marcinkeviciene, L; Gallardo, CA; Meskys, R; Bonnefoy V.; Holmes, DS; Dopson, M

Abstract

Acidithiobacillus caldus has been proposed to play a role in the oxidation of reduced inorganic sulfur compounds (RISCs) produced in industrial biomining of sulfidic minerals. Here, we describe the regulation of a new cluster containing the gene encoding tetrathionate hydrolase (tetH), a key enzyme in the RISC metabolism of this bacterium. The cluster contains five cotranscribed genes, ISac1, rsrR, rsrS, tetH, and doxD, coding for a transposase, a two-component response regulator (RsrR and RsrS), tetrathionate hydrolase, and DoxD, respectively. As shown by quantitative PCR, rsrR, tetH, and doxD are upregulated to different degrees in the presence of tetrathionate. Western blot analysis also indicates upregulation of TetH in the presence of tetrathionate, thiosulfate, and pyrite. The tetH cluster is predicted to have two promoters, both of which are functional in Escherichia coli and one of which was mapped by primer extension. A pyrrolo-quinoline quinone binding domain in TetH was predicted by bioinformatic analysis, and the presence of an o-quinone moiety was experimentally verified, suggesting a mechanism for tetrathionate oxidation. Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Más información

Título según WOS: Regulation of a novel Acidithiobacillus caldus gene cluster involved in metabolism of reduced inorganic sulfur compounds
Título según SCOPUS: Regulation of a novel Acidithiobacillus caldus gene cluster involved in metabolism of reduced inorganic sulfur compounds
Título de la Revista: APPLIED AND ENVIRONMENTAL MICROBIOLOGY
Volumen: 73
Número: 22
Editorial: AMER SOC MICROBIOLOGY
Fecha de publicación: 2007
Página de inicio: 7367
Página final: 7372
Idioma: English
URL: http://aem.asm.org/cgi/doi/10.1128/AEM.01497-07
DOI:

10.1128/AEM.01497-07

Notas: ISI, SCOPUS