COMPLEXES BETWEEN SECA AND SECB, PROTEINS INVOLVED IN PROTEIN EXPORT

SECA 和 SECB 之间的复合物，参与蛋白质输出的蛋白质

• 批准号: 8170217
• 负责人: MARCIA E. NEWCOMER
• 金额: $ 0.1万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8170217
• 关键词: ATP phosphohydrolase; Analytical Centrifugation; Binding; Cell membrane; Complex; Computer Retrieval of Information on Scientific Projects Database; Couples; Coupling; Docking; Electron Spin Resonance Spectroscopy; Escherichia coli; Funding; Grant; Institution; Mediating; Membrane; Molecular Chaperones; Molecular Sieve Chromatography; Motor; Protein Export Pathway; Protein translocation; Proteins; Protomer; Relative (related person); Research; Research Personnel; Resources; Shapes; Site; Source; Spin Labels; System; United States National Institutes of Health; base; interest; light scattering; mutant; stoichiometry

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Protein translocation through the cytoplasmic membrane in E. coli is mediated by the general secretory or Sec system that comprises a channel through the membrane, SecYEG, a motor ATPase, SecA and a chaperone SecB. We are interested in the docking between SecA and SecB. Our studies based on analytical centrifugation and static light scatter in line with size exclusion chromatography indicate that the active SecA : SecB complex has the stoichiometry of two SecA protomers bound to the tetrameric SecB. In addition to its function as a chaperone, SecB couples the ATPase activity of SecA to efficient translocation. We have mutants that populate a complex with a stoichiometry of one SecA protomer to a SecB tetramer and they are defective in the coupling. Our studies with site-directed spin labeling and electron paramagnetic resonance spectroscopy have defined regions of contact between SecA and SecB. However we can not determine the orientation of SecB relative to the SecA subunits. If we could obtain the overall shape of these complexes our attempts to understand the mechanism of coupling would be greatly facilitated. The SecA motor is conserved in all bacterial species and thus its function is of wide interest.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 大肠杆菌中细胞质膜的蛋白质易位是由大分泌或SEC系统介导的，该系统包括通过膜，Secyeg，Motor ATPase，Seca，Seca和伴侣SECB的通道。 我们对SECA和SECB之间的对接感兴趣。我们的研究基于分析离心和静态光散射与尺寸排除色谱线一线表明，活性的SECA：SECB复合物具有与四聚体SECB结合的两个SECA原始体的化学计量。除了其作为伴侣的功能外，SECB还将SECA的ATPase活性融合到有效的易位。我们有一个突变体，可以将一个SECA素的化学计量填充到SECB四聚体中，并且在耦合中有缺陷。我们对位置定向的自旋标记和电子顺磁共振光谱的研究确定了SECA和SECB之间的接触区域。但是，我们无法确定SECB相对于SECA亚基的方向。如果我们能够获得这些络合物的整体形状，我们将极大地促进了解耦合机制的尝试。 SECA电动机在所有细菌物种中都是保守的，因此其功能引起了广泛关注。