Evolution of Function of Bacterial Nucleoid-Associated Proteins

细菌核相关蛋白的功能进化

• 批准号: 1051610
• 负责人: Anne Grove
• 金额: $ 56.32万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1051610&HistoricalAwards=false
• 关键词: Evolution; Function; Bacterial; Nucleoid; Associated

This award supports research focused on understanding the role of important proteins in the structure and function of a bacterial cell. The size of the DNA requires that it be compacted to fit the dimensions of the cell, while still allowing its accessibility to cellular proteins. The bacterial genome is associated with a number of different DNA-binding proteins, including proteins known as HU. Aside from being involved in the organization in DNA, HU proteins function in regulating DNA-dependent processes, such as replication, repair and gene expression and are therefore critical for normal cellular function. In this project, the focus will be on the HU variant encoded by Mycobacterium smegmatis. Mycobacteria encode an unusual two-domain HU protein. What is intriguing about two-domain HU proteins (typically referred to as Hlp, for Histone Like Protein) is that they appear to be encoded only by bacterial species that are particularly adept at resisting environmental stress. For mycobacteria, Hlp has, for example, been reported to be more abundant during dormancy. The goal of this research is to define the functional role of M. smegmatis Hlp, with a specific focus on the role of the lysine-rich extension. Understanding functional roles of mycobacterial Hlp will illuminate a unique aspect of mycobacterial physiology as well as the specific demands of other bacterial species that encode two-domain HU homologs. A combination of DNA-binding assays designed to determine the role of Hlp in DNA compaction are planned, as well as assays aimed at determining the ability of Hlp to protect DNA from damage. M. smegmatis also encodes a protein named Ku, which is expected to function in repair of DNA double strand breaks; Ku shares with Hlp key features of the lysine-rich extension. This shared sequence feature will be exploited to determine the role of the lysine-rich domain in DNA end-joining by both proteins and to ascertain their roles in double strand break repair. A final aim is centered on determining conditions under which Hlp is more abundant and on investigating consequences of Hlp deletion on global gene expression. This line of inquiry is expected to define conditions under which excess Hlp is required and the roles of Hlp in DNA organization, DNA protection, and DNA double strand break repair. This project will integrate research and education by offering the opportunity for both graduate and undergraduate students to acquire research experience and proficiency in techniques associated with analysis of protein-protein and protein-nucleic acid interactions. The involvement of minority students will be emphasized, and students at all levels will be expected to disseminate their research at national meetings.

该奖项支持专注于了解重要蛋白质在细菌细胞结构和功能中的作用的研究。DNA的大小要求它被压缩以适应细胞的尺寸，同时仍然允许其接近细胞蛋白质。细菌基因组与许多不同的DNA结合蛋白相关，包括称为HU的蛋白质。除了参与DNA的组织外，HU蛋白还在调节DNA依赖性过程中发挥作用，例如复制，修复和基因表达，因此对正常细胞功能至关重要。在这个项目中，重点将是由耻垢分枝杆菌编码的HU变体。分枝杆菌编码一种不寻常的双结构域HU蛋白。关于双结构域HU蛋白（通常称为Hlp，代表组蛋白样蛋白）的有趣之处在于，它们似乎只由特别擅长抵抗环境压力的细菌物种编码。例如，对于分枝杆菌，据报道Hlp在休眠期间更丰富。本研究的目的是确定M的功能作用。smeglycine Hlp，特别关注富含赖氨酸的延伸的作用。了解分枝杆菌Hlp的功能作用将阐明分枝杆菌生理学的一个独特方面，以及编码两个结构域HU同源物的其他细菌物种的特定需求。设计用于确定Hlp在DNA压缩中的作用的DNA结合测定的组合被计划，以及旨在确定Hlp保护DNA免受损伤的能力的测定。M. smeglobulin还编码一种名为Ku的蛋白质，预期其在DNA双链断裂的修复中起作用; Ku与Hlp共享富含赖氨酸的延伸的关键特征。这个共享的序列特征将被利用来确定富含赖氨酸的结构域在DNA末端连接的两种蛋白质的作用，并确定它们在双链断裂修复中的作用。最后的目标是集中在确定条件下，HLP是更丰富的，并在全球基因表达的调查HLP缺失的后果。这条调查线预计将确定条件下，需要过量的HLP和HLP在DNA组织，DNA保护和DNA双链断裂修复的作用。该项目将整合研究和教育，为研究生和本科生提供机会，获得研究经验和熟练掌握与蛋白质-蛋白质和蛋白质-核酸相互作用分析相关的技术。将强调少数民族学生的参与，并期望各级学生在全国会议上传播其研究成果。