The respiratory arsenate reductase from Bacillus selenitireducens strain MLS10

E. Afkar; J. Lisak; C. Saltikov; P. Basu; Ronald S. Oremland; J.F. Stolz

doi:10.1016/s0378-1097(03)00609-8

Home/Archive/USGS

USGS · 70025235

The respiratory arsenate reductase from Bacillus selenitireducens strain MLS10

E. Afkar·J. Lisak·C. Saltikov·P. Basu·Ronald S. Oremland·J.F. Stolz

View original source ↗Export metadata ↓

Abstract

The respiratory arsenate reductase from the Gram-positive, haloalkaliphile, Bacillus selenitireducens strain MLS10 was purified and characterized. It is a membrane bound heterodimer (150 kDa) composed of two subunits ArrA (110 kDa) and ArrB (34 kDa), with an apparent K m for arsenate of 34 µM and V max of 2.5 µmol min −1 mg −1 . Optimal activity occurred at pH 9.5 and 150 g l −1 of NaCl. Metal analysis (inductively coupled plasma mass spectrometry) of the holoenzyme and sequence analysis of the catalytic subunit (ArrA; the gene fr which was cloned and sequenced) indicate it is a member of the DMSO reductase family of molybdoproteins.

Explore related subjects

FEMS Microbiology Letters Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

E. Afkar, J. Lisak, C. Saltikov, P. Basu, Ronald S. Oremland, J.F. Stolz. 2003. The respiratory arsenate reductase from Bacillus selenitireducens strain MLS10. https://doi.org/10.1016/s0378-1097(03)00609-8

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2020

Mapping metabolic activity at single cell resolution in intact volcanic fumarole soil

Interactions among microorganisms and their mineralogical substrates govern the structure, function, and emergent properties of microbial communities. These interactions are predicated on spatial relationships, which dictate metabolite exchange and access to key substrates. To quantitatively assess links between spatial relationships and metabolic activity, this study presents a novel approach to map all organisms, the metabolically active subset, and associated mineral grains, all while maintaining spatial integrity of an environmental microbiome. We applied this method at an outgassing fumarole of Vanuatu’s Marum Crater, one of the largest point sources of several environmentally relevant gaseous compounds, including H2O, CO2, and SO2. With increasing distance from the soil-air surface and from mineral grain outer boundaries, organism abundance decreased but the proportion of metabolically active organisms often increased. These protected niches may provide more stable conditions that promote consistent metabolic activity of a streamlined community. Conversely, mineral exteriors accumulate more organisms that may cover a wider range of preferred conditions, implying that only a subset of the community will be active under any particular environmental regime. More broadly, the approach presented here allows investigators to see microbial communities “as they really are” and explore determinants of metabolic activity across a range of microbiomes.

FEMS Microbiology Letters↗

USGS2017

Autotrophic microbial arsenotrophy in arsenic-rich soda lakes

A number of prokaryotes are capable of employing arsenic oxy-anions as either electron acceptors [arsenate; As(V)] or electron donors [arsenite; As(III)] to sustain arsenic-dependent growth (‘arsenotrophy’). A subset of these microorganisms function as either chemoautotrophs or photoautotrophs, whereby they gain sufficient energy from their redox metabolism of arsenic to completely satisfy their carbon needs for growth by autotrophy, that is the fixation of inorganic carbon (e.g. HCO 3 − ) into their biomass. Here we review what has been learned of these processes by investigations we have undertaken in three soda lakes of the western USA and from the physiological characterizations of the relevant bacteria, which include the critical genes involved, such as respiratory arsenate reductase ( arrA ) and the discovery of its arsenite-oxidizing counterpart ( arxA ). When possible, we refer to instances of similar process occurring in other, less extreme ecosystems and by microbes other than haloalkaliphiles.

FEMS Microbiology Letters↗

USGS1992

Molecular cloning and sequence analysis of the gene coding for the 57kDa soluble antigen of the salmonid fish pathogen Renibacterium salmoninarum

The complete sequence coding for the 57-kDa major soluble antigen of the salmonid fish pathogen, Renibacterium salmoninarum , was determined. The gene contained an opening reading frame of 1671 nucleotides coding for a protein of 557 amino acids with a calculated M r value of 57190. The first 26 amino acids constituted a signal peptide. The deduced sequence for amino acid residues 27–61 was in agreement with the 35 N-terminal amino acid residues determined by microsequencing, suggesting the protein in synthesized as a 557-amino acid precursor and processed to produce a mature protein of M r 54505. Two regions of the protein contained imperfect direct repeats. The first region contained two copies of an 81-residue repeat, the second contained five copies of an unrelated 25-residue repeat. Also, a perfect inverted repeat (including three in-frame UAA stop codons) was observed at the carboxyl-terminus of the gene.

FEMS Microbiology Letters↗