Abstract
Acidiphilium spp. are conspicuous dwellers of acidic, metal-rich environments. Indeed, they are among the most metal-resistant organisms; yet little is known about the mechanisms behind the metal tolerance in this genus. Acidiphilium sp. PM is an environmental isolate from Rio Tinto, an acidic, metal-laden river located in southwestern Spain. The characterization of its metal resistance revealed a remarkable ability to tolerate high Ni concentrations. Here we report the screening of a genomic library of Acidiphilium sp. PM to identify genes involved in Ni resistance. This approach revealed seven different genes conferring Ni resistance to E. coli, two of which form an operon encoding the ATP-dependent protease HslVU (ClpQY). This protease was found to enhance resistance to both Ni and Co in E. coli, a function not previously reported. Other Ni-resistance determinants include genes involved in lipopolysaccharide biosynthesis and the synthesis of branched amino acids. The diversity of molecular functions of the genes recovered in the screening suggests that Ni resistance in Acidiphilium sp. PM probably relies on different molecular mechanisms.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ATP-Dependent Proteases / genetics
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Acidiphilium / genetics*
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Acidiphilium / metabolism
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Bacteria / classification
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Bacteria / genetics
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism
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Drug Resistance, Bacterial / genetics*
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Gene Transfer, Horizontal
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Genome, Bacterial / genetics*
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Genomic Library
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Lipopolysaccharides / biosynthesis
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Microbial Viability / drug effects
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Microbial Viability / genetics
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Molecular Sequence Data
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Nickel / metabolism
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Nickel / pharmacology*
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Open Reading Frames / genetics
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Operon
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Phylogeny
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Rivers / microbiology
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Sequence Analysis, DNA
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Spain
Substances
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Bacterial Proteins
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Lipopolysaccharides
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Nickel
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ATP-Dependent Proteases
Associated data
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GENBANK/KC110840
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GENBANK/KC110841
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GENBANK/KC110842
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GENBANK/KC110843
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GENBANK/KC110844
Grants and funding
This work was funded by European Research Council advanced grant ERC 250350 and Spanish Ministry of Science and Innovation grants CGL2009-11059, CGL-2009-10756/BOS and CONSOLIDER Ingenio 2010 (“The Metagenome of the Iberian Peninsula”, CE-CSD2007-00005). PSMU is supported by a “Calvo Rodés” fellowship from the National Institute for Aerospace Technology (INTA). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.