METALLOREGULATION OF HEAVY METAL RESISTANCE GENES IN BACTERIA

细菌中重金属抗性基因的金属调控

• 批准号: 6586677
• 负责人: ROBERT A SCOTT
• 金额: $ 14.32万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2003-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6586677
• 关键词: bacteria; biomaterials; biomedical resource; genome; proteins; spectrometry; structural biology

We propose to study the interaction of metals with proteins involved in regulated heavy metal resistance in bacteria. We have chosen two well-studied examples: the gene products of the mer operon from Gram negative transposon Tn21 that confers mercury resistance; and the gene products of the ars operon from E. coli plasmid R773 that confers arsenical and antimonial resistance. In the mer operon, Hg(II), Cd(II), and Zn(II) interactions with the MerR metalloregulatory protein and mutants that have altered metal activation specificities will be compared at the level of active-site structure. In the ars operon, As(III) and Sb(III) binding sites on ArsR and ArsD, two co-regulatory proteins that control ars gene expression by an arsenite/antimonite-dependent mechanism, and ArsA, the ATP-dependent and M(III)-activated arsenite/antimonite ion transporter, will be defined. Site-directed mutagenesis will be used to determine the residues involved in As(III) and Sb(III) binding sites.

我们建议研究金属与蛋白质的相互作用 参与调节细菌对重金属的抵抗力。 我们有 选择了两个经过充分研究的例子：mer操纵子的基因产物 来自赋予汞抗性的革兰氏阴性转座子 Tn21； 以及来自大肠杆菌质粒 R773 的 ars 操纵子的基因产物 赋予砷和锑抗性。 在 mer 操纵子中， Hg(II)、Cd(II) 和 Zn(II) 与 MerR 的相互作用 金属调节蛋白和改变金属的突变体 激活特异性将在活性位点水平上进行比较 结构。 在 ars 操纵子中，As(III) 和 Sb(III) 结合位点 ArsR 和 ArsD，两种控制 ars 基因的共调控蛋白 通过亚砷酸盐/锑酸盐依赖性机制表达，和ArsA， ATP 依赖性和 M(III) 激活的亚砷酸根/锑酸根离子 运输者，将被定义。 将使用定点诱变 确定参与 As(III) 和 Sb(III) 结合的残基 网站。