title: Control of zinc homeostasis in Agrobacterium tumefaciens via zur and the zinc uptake genes znuABC and zinT.
abstract: The Agrobacterium tumefaciens zinc uptake regulator (Zur) was shown to negatively regulate the zinc uptake genes znuABC, encoding a zinc transport system belonging to the ATP-binding cassette (ABC) transporter family, and zinT, which encodes a periplasmic zinc-binding protein. The expression of znuABC and zinT was inducible when cells were grown in medium containing a metal chelator (EDTA), and this induction was shown to be specific for zinc depletion. The expression of znuABC was reduced in response to increased zinc in a dose-dependent manner, and zinT had a less pronounced but similar pattern of zinc-regulated expression. The inactivation of zur led to constitutively high expression of znuABC and zinT. In addition, a zur mutant had an increased total zinc content compared to the WT NTL4 strain, whereas the inactivation of zinT caused a reduction in the total zinc content. The zinT gene is shown to play a dominant role and to be more important than znuA and znuB for A. tumefaciens survival under zinc deprivation. ZinT can function even when ZnuABC is inactivated. However, mutations in zur, znuA, znuB or zinT did not affect the virulence of A. tumefaciens.
authors.affiliation: Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.|Applied Biological Sciences, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand.
authors.forename: Sakkarin
authors.initials: S
authors.lastname: Bhubhanil
authors.affiliation: Laboratory of Pharmacology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.|Environmental Toxicology, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand.|Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.
authors.forename: Panida
authors.initials: P
authors.lastname: Sittipo
authors.affiliation: Laboratory of Pharmacology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.|Environmental Toxicology, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand.|Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.
authors.forename: Paweena
authors.initials: P
authors.lastname: Chaoprasid
authors.affiliation: Laboratory of Pharmacology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.
authors.forename: Sumontha
authors.initials: S
authors.lastname: Nookabkaew
authors.affiliation: 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.|Applied Biological Sciences, Chulabhorn Graduate Institute, Lak Si, Bangkok 10210, Thailand.
authors.forename: Rojana
authors.initials: R
authors.lastname: Sukchawalit
authors.affiliation: Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, 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.forename: Skorn
authors.initials: S
authors.lastname: Mongkolsuk
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006706:Homeostasis; D015032:Zinc / Q000378:metabolism*
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C017800:zinc-binding protein; D015032:Zinc