title: Roles of Agrobacterium tumefaciens C58 ZntA and ZntB and the transcriptional regulator ZntR in controlling Cd2+/Zn2+/Co2+ resistance and the peroxide stress response.
abstract: The putative zinc exporters ZntA (a P1B-type ATPase) and ZntB (2-TM-GxN family) in Agrobacterium tumefaciens were characterized. The expression of the zntA gene is inducible by CdCl2, ZnCl2 and CoCl2, of which CdCl2 is the most potent inducer, whereas zntB is constitutively expressed. The metal-induced expression of zntA is controlled by the MerR-like regulator ZntR. The zntA and zntR mutants were highly sensitive to CdCl2 and ZnCl2, and CoCl2 sensitivity was demonstrated to a lesser extent. By contrast, the zntB mutant showed similar levels of metal resistance to the WT strain. Even in the zntA mutant background, zntB did not play an apparent role in metal resistance under the conditions tested. The inactivation of zntA increased the accumulation of intracellular cadmium and zinc, and conferred hyper-resistance to H2O2. Thus, the metal transporter ZntA and its regulator ZntR are important for controlling zinc homeostasis and cadmium and cobalt detoxification. The loss of either the zntA or zntR gene did not affect the virulence of A. tumefaciens in Nicotiana benthamiana.
authors: Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.
authors: Paweena
authors: P
authors: Chaoprasid
authors: Laboratory of Pharmacology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.
authors: Sumontha
authors: S
authors: Nookabkaew
authors: Applied Biological Sciences, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand.|Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.|Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.
authors: Rojana
authors: R
authors: Sukchawalit
authors: Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.|Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.|Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors: Skorn
authors: S
authors: Mongkolsuk
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002104:Cadmium / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D003035:Cobalt / Q000378:metabolism*; D004268:DNA-Binding Proteins; D015964:Gene Expression Regulation, Bacterial; D006861:Hydrogen Peroxide / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D018384:Oxidative Stress; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism*; D014774:Virulence / Q000235:genetics; D015032:Zinc / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D014157:Transcription Factors; C504004:Ttf1 protein, mouse; C017800:zinc-binding protein; D002104:Cadmium; D003035:Cobalt; D006861:Hydrogen Peroxide; D000251:Adenosine Triphosphatases; C109898:Zn(II)-translocating P-type ATPase; D015032:Zinc