title: Arsenic resistance strategy in Pantoea sp. IMH: Organization, function and evolution of ars genes.
abstract: Pantoea sp. IMH is the only bacterium found in genus Pantoea with a high As resistance capacity, but its molecular mechanism is unknown. Herein, the organization, function, and evolution of ars genes in IMH are studied starting with analysis of the whole genome. Two ars systems - ars1 (arsR1B1C1H1) and ars2 (arsR2B2C2H2) - with low sequence homology and two arsC-like genes, were found in the IMH genome. Both ars1 and ars2 are involved in the As resistance, where ars1 is the major contributor at 15 °C and ars2 at 30 °C. The difference in the behavior of these two ars systems is attributed to the disparate activities of their arsR promoters at different temperatures. Sequence analysis based on concatenated ArsRBC indicates that ars1 and ars2 clusters may be acquired from Franconibacter helveticus LMG23732 and Serratia marcescens (plasmid R478), respectively, by horizontal gene transfer (HGT). Nevertheless, two arsC-like genes, probably arising from the duplication of arsC, do not contribute to the As resistance. Our results indicate that Pantoea sp. IMH acquired two different As resistance genetic systems by HGT, allowing the colonization of changing ecosystems, and highlighting the flexible adaptation of microorganisms to resist As.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Liying
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xuliang
authors.initials: X
authors.lastname: Zhuang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Zhuang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Chuanyong
authors.initials: C
authors.lastname: Jing
mesh_terms: D000222:Adaptation, Physiological; D001151:Arsenic / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D024881:Drug Resistance, Bacterial; D019143:Evolution, Molecular; D015964:Gene Expression Regulation, Bacterial; D022761:Gene Transfer, Horizontal; D005810:Multigene Family; D020636:Pantoea / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D001151:Arsenic