title: A chromosomal ars operon homologue of Pseudomonas aeruginosa confers increased resistance to arsenic and antimony in Escherichia coli.
abstract: Operons encoding homologous arsenic-resistance determinants (ars) have been discovered in bacterial plasmids from Gram-positive and Gram-negative organisms, as well as in the Escherichia coli chromosome. However, evidence for this arsenic-resistance determinant in the medically and environmentally important bacterial species Pseudomonas aeruginosa is conflicting. Here the identification of a P. aeruginosa chromosomal ars operon homologue via cloning and complementation of an E. coli ars mutant is reported. The P. aeruginosa chromosomal ars operon contains three potential ORFs encoding proteins with significant sequence similarity to those encoded by the arsR, arsB and arsC genes of the plasmid-based and E. coli chromosomal ars operons. The cloned P. aeruginosa chromosomal ars operon confers augmented resistance to arsenic and antimony oxyanions in an E. coli arsB mutant and in wild-type P. aeruginosa. Expression of the operon was induced by arsenite at the mRNA level. DNA sequences homologous with this operon were detected in some, but not all, species of the genus Pseudomonas, suggesting that its conservation follows their taxonomic-based evolution.
authors.forename: Jie
authors.initials: J
authors.lastname: Cai
authors.forename: Kirsty
authors.initials: K
authors.lastname: Salmon
authors.forename: Michael S
authors.initials: MS
authors.lastname: DuBow
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000965:Antimony / Q000494:pharmacology*; D001151:Arsenic / Q000494:pharmacology*; D053501:Arsenite Transporting ATPases; D001483:Base Sequence; D015139:Blotting, Southern; D017124:Conserved Sequence; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005816:Genetic Complementation Test; D019077:Helix-Turn-Helix Motifs / Q000235:genetics; D016623:Ion Pumps; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes; D016366:Open Reading Frames / Q000235:genetics; D009876:Operon / Q000235:genetics; D011549:Pseudomonas / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D016623:Ion Pumps; D009097:Multienzyme Complexes; D000965:Antimony; D000251:Adenosine Triphosphatases; D053501:Arsenite Transporting ATPases; D001151:Arsenic