Structure-Function of Heavy Metal Transport CPx-ATPases

重金属转运 CPx-ATP 酶的结构-功能

• 批准号: 0235165
• 负责人: Jose Arguello
• 金额: $ 84.24万
• 依托单位: Worcester Polytechnic Institute
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0235165&HistoricalAwards=false
• 关键词: Structure; Function; Heavy; Metal; Transport

The goal of this project is to understand the functional mechanism of heavy metal transport CPx-ATPases. These P-type ATPases transport heavy metals (ions of Cu, Ag, Zn, Co, Cd, Pb) across biomembranes. Found in all life kingdoms, these key enzymes are involved in micronutrient metal homeostasis. The transport stoichiometry, the determinants of metal ion specificity, and the regulatory mechanisms of CPx-ATPases are not known. This project aims to identify key structural features involved in ion selectivity and activity regulation. Simpler CPx-ATPases found in procaryotes will be used as models in these studies: Cu-ATPases from A. fulgidus, a Co-ATPase from A. pernix, and a Zn-ATPase from H. influenzae. A. fulgidus and A. pernix are extremophilic archaea. Experiments will be performed to test whether conserved sequences in the transmembrane region of CPx-ATPases determine ion specificity. CPx-ATPases have cytoplasmic N-terminal metal-binding domains, in addition to the transmembrane CPx site. The possible regulatory role of the metal-binding domain in enzyme kinetics will be studied. This project will also involve testing whether a metal chaperone molecule delivers the metal to the transport site. The fourth goal of this project is to determine the structure of a CPx-ATPase using X-ray crystallography. The structure of CPx-ATPases at atomic resolution would greatly enhance understanding the mechanism of heavy metal transport.Broader Impact: The project will contribute to an understanding of heavy metal homeostasis. Insight gained in metal selectivity might facilitate the design of metal bioremediation processes and the management of plant and animal mineral nutrition. This research will also contribute to ongoing educational activities (undergraduate teaching, curriculum development and summer research). Moreover, undergraduate and graduate students will perform major parts of this project.

该项目的目的是了解重金属运输CPX-ATPase的功能机制。这些P型ATP酶在生物膜上运输重金属（Cu，Ag，Zn，Co，Cd，Pb）的重金属。这些关键酶在所有生命王国中发现，都与微量营养素的金属稳态有关。尚不清楚转运化学计量，金属离子特异性的决定因素和CPX-ATPase的调节机制。该项目旨在确定与离子选择性和活动调节有关的关键结构特征。在这些研究中发现的Procaryotes中发现的更简单的CPX-ATP酶将用作模型：来自A. fulgidus的Cu-atpases，A。Pernix的共同ATPase和来自流感H. h. A. fulgidus和A. pernix是极端的古细菌。将进行实验以测试CPX-ATP酶的跨膜区域中的保守序列确定离子特异性。除跨膜CPX位点外，CPX-ATP酶具有细胞质N末端金属结合结构域。将研究金属结合结构域在酶动力学中的可能调节作用。该项目还将涉及测试金属伴侣分子是否将金属传递到运输部位。该项目的第四个目标是使用X射线晶体学确定CPX-ATPase的结构。原子分辨率上CPX-ATP酶的结构将大大增强理解重金属运输的机制。BoaderImpact：该项目将有助于理解重金属稳态。在金属选择性方面获得的洞察力可能有助于设计金属生物修复过程以及动植物矿物营养的管理。这项研究还将有助于持续的教育活动（本科教学，课程发展和夏季研究）。此外，本科生和研究生将执行该项目的主要部分。