CysZ proteins_A family of sulfate transporters with remarkable architecture

CysZ蛋白_具有卓越结构的硫酸盐转运蛋白家族

• 批准号: 8509215
• 负责人: Filippo Mancia
• 金额: $ 4.51万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8509215
• 关键词: ATP-Binding Cassette Transporters; Anions; Architecture; Asses; Assimilations; Bacteria; Binding; Binding Sites; Biological Assay; Cell Survival; Cell membrane; Cells; Charge; Color; Coupled; Coupling; Cysteine; Detergents; Electrophysiology (science); Elements; Employee Strikes; Environment; Event; Exhibits; Family; Gene Family; Gray unit of radiation dose; Homologous Gene; Inorganic Sulfates; Ion Transport; Ions; Left; Lipid Bilayers; Lipids; Location; Measurement; Membrane; Membrane Proteins; Molecular Sieve Chromatography; Molecular Weight; Monitor; Mutagenesis; Oranges; Oxygen; Pathway interactions; Permeability; Probability; Process; Property; Proteins; Protomer; Refractive Indices; Reporting; Resolution; Role; Seawater; Series; Side; Solutions; Structure; Sulfur; Testing; Unspecified or Sulfate Ion Sulfates; Variant; Water; base; crosslink; dimer; extracellular; in vivo; light scattering; mutant; novel; periplasm; reconstitution; research study; sulfate transporter; uptake

DESCRIPTION (provided by applicant): Sulfur is an essential element for cell survival, and its most readily available form in the environment is sulfate. There are three known families of sulfate transporters that are responsible for intracellular uptake of this ion. One family belongs o the ABC transporter family and is thought to function when the concentration of extracellular sulfate is low and energy is required for the process to occur. A second one belongs to the SulP class of major facilitator superfamily transporters. A third family are the products of the bacteril CysZ gene family. SulPs and CysZ are thought to be active when the concentration of sulfate in the environment is high enough to allow its entry inside the cell by a chemiosmotic driven mechanism. We have determined the crystal structure to 2.1¿ resolution of CysZ from Idiomarina loihiensis, a gram- negative deep-sea water bacterium and have established a functional assay for this protein. To the best of our knowledge this represents the first report ofa snapshot of a sulfate transporter at atomic resolution. The structure shows an unexpected and novel topology in which the protein assembles as a tight symmetric dimer across the plane of the membrane, so that the extracellular and intracellular sides of the molecule are the same. Two dimers pack against each other along hydrophobic helices protruding in and parallel to the membrane, to form a tetrameric assembly. The structure shows bound sulfate but the mechanism of transport has yet to be unveiled. We plan to perform experiments aimed at validating and understanding the remarkable architecture of CysZ (Aim 1). We also plan to understand how sulfate is transported across the membrane (Aim 2), and to characterize the factors that trigger an opening of the CysZ ion conductance pore (Aim 3).

描述（由适用提供）：硫是细胞存活的重要元素，其在环境中最容易获得的形式是硫酸盐。有三个已知的硫酸盐转运蛋白家族负责该离子的细胞内摄取。一个家族属于ABC转运蛋白家族，当细胞外硫酸盐的浓度较低时，该过程需要能量才能进行。第二个属于主要促进剂超家族转运蛋白的硫酸类别。第三个家庭是细菌Cysz基因家族的产物。当硫酸盐在环境中的浓度足够高以使其通过化学感染驱动机制允许其进入细胞中时，硫酸盐和Cysz被认为是活跃的。我们已经确定了从革兰氏阴性深海水细菌的习惯性loihiensis中cysz的晶体结构，并确定了该蛋白质的功能评估。据我们所知，这代表了原子分辨率的硫酸盐转运蛋白快照的第一个报告。该结构显示出意外的新拓扑结构，其中蛋白质在整个膜平面上以紧密的对称二聚体聚集，以使分子的细胞外和细胞内侧相同。沿疏水螺旋伸出并平行于膜形成四聚体，形成四聚体组件。该结构显示出结合的硫酸盐，但运输机理尚未公布。我们计划执行旨在验证和了解Cysz的非凡体系结构的实验（AIM 1）。我们还计划了解如何在整个膜上运输硫酸盐（AIM 2），并表征触发Cysz离子电导孔口开放的因素（AIM 3）。