STRUCTURAL BASIS OF BACTERIORHODOPSIN BIOGENESIS

细菌视紫红质生物发生的结构基础

• 批准号: 6457565
• 负责人: MARK P KREBS
• 金额: $ 11.73万
• 依托单位: ILLINOIS STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-15 至 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6457565
• 关键词: Halobacteriaceae; bacterial genetics; bacteriorhodopsins; gene mutation; membrane biogenesis; molecular assembly /self assembly; protein biosynthesis; protein folding; structural biology

DESCRIPTION (provided by applicant): The long-term goal of the proposed research is understand the structural basis of membrane protein biogenesis. The focus is on the polytopic (multispanning) membrane protein, bacteriorhodopsin, an integral membrane protein produced by the archaeon Halobacteriurn salinarum. This protein folds to form a bundle of seven transmembrane alpha-helices, binds retinal and assembles in a two-dimensional crystalline lattice known as the purple membrane. Bacteriorhodopsin is a model for understanding membrane protein insertion, folding and assembly because its three-dimensional structure is known at high resolution in the native membrane environment. The objective in this proposal is to test in vivo whether bacteriorhodopsin fits a two-stage model in which interactions between transmembrane segments are the primary determinant of folding and assembly. The specific aims are (1) to introduce mutations throughout BR by a saturation mutagenesis approach implemented in preliminary studies; (II) to identify those residues at which substitutions can be tolerated without affecting the formation of BR from BO and retinal; and (III) to determine residues at which substitutions can be tolerated without affecting the assembly of the BR lattice. The results from this analysis will be compared with the three-dimensional structure of BR to test whether the predictions of the two-stage model are confirmed. These studies are expected to yield important new information on the structural basis of integral membrane protein folding and assembly in the cell.

描述（由申请人提供）：拟议的长期目标 研究理解膜蛋白生物发生的结构基础。这 重点放在多重（多层）膜蛋白，细菌紫红质， 由盐片盐酸盐生成的整体膜蛋白。 该蛋白质折叠以形成七个跨膜α-螺旋的束，结合 视网膜和组装在二维晶格中，称为 紫色膜。细菌紫红素是理解膜的模型 蛋白质插入，折叠和组装，因为其三维结构 在天然膜环境中以高分辨率为止。目标 在此建议中是在体内测试细菌紫红素是否适合两个阶段 模型中，跨膜段之间的相互作用是主要的 折叠和组装的决定因素。 具体目的是（1）通过饱和度引入整个BR的突变 初步研究实施的诱变方法； （ii）确定这些 可以容忍替代的残留物而不会影响 BO和视网膜的BR形成； （iii）确定残留物 可以在不影响BR组装的情况下宽容替换 格子。该分析的结果将与 BR的三维结构以测试是否预测 确认了两阶段模型。这些研究有望产生重要 关于整体膜蛋白折叠的结构基础的新信息 和组装在单元格中。