Organization and regulation of the arsenite oxidase operon of the moderately acidophilic and facultative chemoautotrophic Thiomonas arsenitoxydans

Extremophiles ◽  
2013 ◽  
Vol 17 (6) ◽  
pp. 911-920 ◽  
Author(s):  
Djamila Slyemi ◽  
Danielle Moinier ◽  
Emmanuel Talla ◽  
Violaine Bonnefoy
Keyword(s):  
Arsenite Oxidase ◽  
Moderately Acidophilic

Regulation of the Arsenic Oxidation Encoding Genes of a Moderately Acidophilic, Facultative Chemolithoautotrophic Thiomonas sp.

2007 ◽  
Vol 20-21 ◽  
pp. 427-430 ◽  
Author(s):  
Djamila Slyemi ◽  
Jeanine Ratouchniak ◽  
Violaine Bonnefoy
Keyword(s):  
Genome Sequence ◽  
Transcriptional Regulator ◽  
Mining Site ◽  
Arsenite Oxidase ◽  
Cytochromes C ◽  
Genes Encoding ◽  
Arsenic Oxidation ◽  
Encoding Genes ◽  
Moderately Acidophilic

At the abandoned mining site of Carnoulès (Gard, France), weathering of the arsenopyrite rich tailings leads to the formation of acidic effluents heavily loaded with arsenite (As(III)). However, further downstream, the As(III) concentration decreases while the sediments are richer in arsenate (As(V)). A Thiomonas sp. able to oxidize arsenite to arsenate has been isolated and characterized. The aoxA and aoxB genes encoding the two subunits of this enzyme belong to an operon. Analysis of the genome sequence (Genoscope, Ivry, France) shows that this operon encodes also two cytochromes c, which could be the physiological partners of the arsenite oxidase, and a transcriptional regulator belonging to the metalloregulator ArsR/SmtB family, which could control the expression of the aox operon. The expression of this operon is higher in the presence than in the absence of As(III) and appears also to be repressed in the presence of thiosulfate, a more energetic substrate.

scholarly journals An ArsR/SmtB Family Member Is Involved in the Regulation by Arsenic of the Arsenite Oxidase Operon in Thiomonas arsenitoxydans

2014 ◽  
Vol 80 (20) ◽  
pp. 6413-6426 ◽  
Author(s):  
Danielle Moinier ◽  
Djamila Slyemi ◽  
Deborah Byrne ◽  
Sabrina Lignon ◽  
Régine Lebrun ◽  
...  
Keyword(s):  
Family Member ◽  
Regulatory Region ◽  
The Other ◽  
Cysteine Residues ◽  
Transcriptional Interference ◽  
Tight Control ◽  
Arsenite Oxidase ◽  
Content Type ◽  
Genetic Organization ◽  
Moderately Acidophilic

ABSTRACTThe genetic organization of theaioBAoperon, encoding the arsenite oxidase of the moderately acidophilic and facultative chemoautotrophic bacteriumThiomonas arsenitoxydans, is different from that of theaioBAoperon in the other arsenite oxidizers, in that it encodes AioF, a metalloprotein belonging to the ArsR/SmtB family. AioF is stabilized by arsenite, arsenate, or antimonite but not molybdate. Arsenic is tightly attached to AioF, likely by cysteine residues. When loaded with arsenite or arsenate, AioF is able to bind specifically to the regulatory region of theaiooperon at two distinct positions. InThiomonas arsenitoxydans, the promoters ofaioXandaioBare convergent, suggesting that transcriptional interference occurs. These results indicate that the regulation of theaioBAoperon is more complex inThiomonas arsenitoxydansthan in the otheraioBAcontaining arsenite oxidizers and that the arsenic binding protein AioF is involved in this regulation. On the basis of these data, a model to explain the tight control ofaioBAexpression by arsenic inThiomonas arsenitoxydansis proposed.

Constitutive arsenite oxidase expression detected in arsenic-hypertolerant Pseudomonas xanthomarina S11

2015 ◽  
Vol 166 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Sandrine Koechler ◽  
Florence Arsène-Ploetze ◽  
Céline Brochier-Armanet ◽  
Florence Goulhen-Chollet ◽  
Audrey Heinrich-Salmeron ◽  
...  
Keyword(s):  
Arsenite Oxidase

scholarly journals Molybdenum-Containing Arsenite Oxidase of the Chemolithoautotrophic Arsenite Oxidizer NT-26

2004 ◽  
Vol 186 (6) ◽  
pp. 1614-1619 ◽  
Author(s):  
Joanne M. Santini ◽  
Rachel N. vanden Hoven
Keyword(s):  
Secretory Pathway ◽  
Alcaligenes Faecalis ◽  
Sequence Analyses ◽  
Arsenite Oxidase ◽  
Sulfolobus Tokodaii ◽  
Aeropyrum Pernix ◽  
Native Molecular Mass ◽  
Iron Sulfur ◽  
Dimethyl Sulfoxide Reductase

ABSTRACT The chemolithoautotroph NT-26 oxidizes arsenite to arsenate by using a periplasmic arsenite oxidase. Purification and preliminary characterization of the enzyme revealed that it (i) contains two heterologous subunits, AroA (98 kDa) and AroB (14 kDa); (ii) has a native molecular mass of 219 kDa, suggesting an α2β2 configuration; and (iii) contains two molybdenum and 9 or 10 iron atoms per α2β2 unit. The genes that encode the enzyme have been cloned and sequenced. Sequence analyses revealed similarities to the arsenite oxidase of Alcaligenes faecalis, the putative arsenite oxidase of the beta-proteobacterium ULPAs1, and putative proteins of Aeropyrum pernix, Sulfolobus tokodaii, and Chloroflexus aurantiacus. Interestingly, the AroA subunit was found to be similar to the molybdenum-containing subunits of enzymes in the dimethyl sulfoxide reductase family, whereas the AroB subunit was found to be similar to the Rieske iron-sulfur proteins of cytochrome bc 1 and b 6 f complexes. The NT-26 arsenite oxidase is probably exported to the periplasm via the Tat secretory pathway, with the AroB leader sequence used for export. Confirmation that NT-26 obtains energy from the oxidation of arsenite was obtained, as an aroA mutant was unable to grow chemolithoautotrophically with arsenite. This mutant could grow heterotrophically in the presence of arsenite; however, the arsenite was not oxidized to arsenate.

scholarly journals Heterologously expressed arsenite oxidase: A system to study biogenesis and structure/function relationships of the enzyme family

2012 ◽  
Vol 1817 (9) ◽  
pp. 1701-1708 ◽  
Author(s):  
Robert van Lis ◽  
Wolfgang Nitschke ◽  
Thomas P. Warelow ◽  
Line Capowiez ◽  
Joanne M. Santini ◽  
...  
Keyword(s):  
Structure Function ◽  
Arsenite Oxidase ◽  
Enzyme Family

scholarly journals The Small Subunit AroB of Arsenite Oxidase

2010 ◽  
Vol 285 (27) ◽  
pp. 20442-20451 ◽  
Author(s):  
Simon Duval ◽  
Joanne M. Santini ◽  
Wolfgang Nitschke ◽  
Russ Hille ◽  
Barbara Schoepp-Cothenet
Keyword(s):  
Small Subunit ◽  
Arsenite Oxidase

scholarly journals Effect of arsenite on swimming motility delays surface colonization in Herminiimonas arsenicoxydans

Microbiology ◽  
2010 ◽  
Vol 156 (8) ◽  
pp. 2336-2342 ◽  
Author(s):  
M. Marchal ◽  
R. Briandet ◽  
S. Koechler ◽  
B. Kammerer ◽  
P. N. Bertin
Keyword(s):  
Laser Scanning ◽  
Time Course ◽  
Wild Type Strain ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Wild Type ◽  
Arsenite Oxidase ◽  
Swimming Motility ◽  
In The Wild ◽  
Biofilm Development

Herminiimonas arsenicoxydans is a Gram-negative bacterium able to detoxify arsenic-contaminated environments by oxidizing arsenite [As(III)] to arsenate [As(V)] and by scavenging arsenic ions in an extracellular matrix. Its motility and colonization behaviour have been previously suggested to be influenced by arsenite. Using time-course confocal laser scanning microscopy, we investigated its biofilm development in the absence and presence of arsenite. Arsenite was shown to delay biofilm initiation in the wild-type strain; this was partly explained by its toxicity, which caused an increased growth lag time. However, this delayed adhesion step in the presence of arsenite was not observed in either a swimming motility defective fliL mutant or an arsenite oxidase defective aoxB mutant; both strains displayed the wild-type surface properties and growth capacities. We propose that during the biofilm formation process arsenite acts on swimming motility as a result of the arsenite oxidase activity, preventing the switch between planktonic and sessile lifestyles. Our study therefore highlights the existence, under arsenite exposure, of a competition between swimming motility, resulting from arsenite oxidation, and biofilm initiation.

scholarly journals Cold-adapted arsenite oxidase from a psychrotolerant Polaromonas species

Metallomics ◽  
2013 ◽  
Vol 5 (4) ◽  
pp. 318-324 ◽  
Author(s):  
Thomas H. Osborne ◽  
Matthew D. Heath ◽  
Andrew C. R. Martin ◽  
Jaroslaw A. Pankowski ◽  
Karen A. Hudson-Edwards ◽  
...  
Keyword(s):  
Arsenite Oxidase ◽  
Cold Adapted

scholarly journals Identification of a Novel Arsenite Oxidase Gene, arxA, in the Haloalkaliphilic, Arsenite-Oxidizing Bacterium Alkalilimnicola ehrlichii Strain MLHE-1

2010 ◽  
Vol 192 (14) ◽  
pp. 3755-3762 ◽  
Author(s):  
Kamrun Zargar ◽  
Shelley Hoeft ◽  
Ronald Oremland ◽  
Chad W. Saltikov
Keyword(s):  
Genetic System ◽  
Mono Lake ◽  
Genetic Identification ◽  
Transcription Analysis ◽  
Oxidase Gene ◽  
Arsenite Oxidation ◽  
Dmso Reductase ◽  
Arsenite Oxidase ◽  
New Type

ABSTRACT Although arsenic is highly toxic to most organisms, certain prokaryotes are known to grow on and respire toxic metalloids of arsenic (i.e., arsenate and arsenite). Two enzymes are known to be required for this arsenic-based metabolism: (i) the arsenate respiratory reductase (ArrA) and (ii) arsenite oxidase (AoxB). Both catalytic enzymes contain molybdopterin cofactors and form distinct phylogenetic clades (ArrA and AoxB) within the dimethyl sulfoxide (DMSO) reductase family of enzymes. Here we report on the genetic identification of a “new” type of arsenite oxidase that fills a phylogenetic gap between the ArrA and AoxB clades of arsenic metabolic enzymes. This “new” arsenite oxidase is referred to as ArxA and was identified in the genome sequence of the Mono Lake isolate Alkalilimnicola ehrlichii MLHE-1, a chemolithoautotroph that can couple arsenite oxidation to nitrate reduction. A genetic system was developed for MLHE-1 and used to show that arxA (gene locus ID mlg_0216) was required for chemoautotrophic arsenite oxidation. Transcription analysis also showed that mlg_0216 was only expressed under anaerobic conditions in the presence of arsenite. The mlg_0216 gene is referred to as arxA because of its greater homology to arrA relative to aoxB and previous reports that implicated Mlg_0216 (ArxA) of MLHE-1 in reversible arsenite oxidation and arsenate reduction in vitro. Our results and past observations support the position that ArxA is a distinct clade within the DMSO reductase family of proteins. These results raise further questions about the evolutionary relationships between arsenite oxidases (AoxB) and arsenate respiratory reductases (ArrA).

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