RIG: Structural Biology of the Soil Bacterium M. xanthus Development and Motility

RIG：土壤细菌 M. xanthus 发育和运动的结构生物学

• 批准号: 0918807
• 负责人: Ernesto Fuentes
• 金额: $ 17.5万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0918807&HistoricalAwards=false
• 关键词: RIG; Structural; Biology; Soil; Bacterium

Intellectual merit. The soil bacterium Myxococcus xanthus is a model organism for studying prokaryotic chemosensory signal transduction. This bacterium contains eight chemosensory systems that regulate developmental gene expression, motility, and biofilm formation. The focus of this project is to elucidate the regulatory mechanisms of signal transduction in the Che3 and Frz chemosensory systems, which are critical for spore development and motility, respectively. The Che3 system regulates transcription of important developmental genes in response to outer membrane stress. This regulation is derived through the recently identified regulatory protein, CrdC (chemosensory regulator of development protein C). This investigator's preliminary findings indicate that CrdC modulates downstream signaling and sporulation by forming a regulatory complex with CheW3. Solution NMR methods will be used to determine the structures of CheW3 and CrdC and define the residues that mediate their interaction. These structures will provide the foundation for understanding the biochemical and structural features required for Che3 chemosensory regulation. The Frz chemosensory system and the protein MglA are critical regulators of motility. The Frz system is capable of activating MglA by an unknown mechanism. Activated MglA, in turn, is critical for regulating motility through the interaction with downstream effector proteins. The MglA protein has homology to eukaryotic GTPases, but its ability to bind and hydrolyze guanine nucleotides has not been determined. This study will use biochemical and biophysical approaches to define the nucleotide-binding properties of MglA and the requirements for interacting with downstream signaling effectors. The results from these fundamental studies will provide key structural and biophysical insights into the mechanism of Che3 and Frz chemosensory regulation and the framework for future research towards developing a comprehensive structural and mechanistic picture of chemosensory regulation in M. xanthus. Broader impacts. Exciting students about science and biochemical research is critical for fostering science-based careers. The principal investigator will engage students early in their undergraduate career in two ways. First, he will design and implement a new laboratory section for the existing experimental Biochemistry course that features biophysical experiments. This novel section will complement the existing didactic courses in biophysics and expose undergraduate students to quantitative methods and biophysical techniques. Second, he will initiate a new program to provide summer research opportunities to under-represented minority students. This program will be funded by the RIG grant and the Department of Biochemistry. Collectively, these strategies will help provide the necessary academic and research background necessary to attract and retain talented undergraduate students in the sciences.

智力上的优点。 土壤细菌黄色粘球菌是研究原核生物化学感受信号转导的模式生物。 这种细菌含有八个化学感受系统，调节发育基因表达，运动和生物膜形成。 该项目的重点是阐明Che 3和Frz化学感受系统中的信号转导调节机制，这两个系统分别对孢子发育和运动性至关重要。 Che3系统调节重要发育基因的转录以响应外膜胁迫。 这种调节是通过最近鉴定的调节蛋白CrdC（发育蛋白C的化学感受调节剂）衍生的。 该研究者的初步发现表明，CrdC通过与CheW3形成调节复合物来调节下游信号传导和孢子形成。 溶液NMR方法将用于确定CheW3和CrdC的结构，并确定介导其相互作用的残基。 这些结构将为了解Che 3化学感受调节所需的生化和结构特征提供基础。 Frz化学感受系统和蛋白质MglA是运动的关键调节剂。 Frz系统能够通过未知的机制激活MglA。 活化的MglA反过来对于通过与下游效应蛋白的相互作用来调节运动性是关键的。 MglA蛋白与真核生物GTP酶具有同源性，但其结合和水解鸟嘌呤核苷酸的能力尚未确定。 本研究将使用生物化学和生物物理方法来定义MglA的核苷酸结合特性以及与下游信号效应物相互作用的要求。 这些基础研究的结果将为Che 3和Frz化学感受调节机制提供关键的结构和生物物理见解，并为未来的研究提供框架，以开发M中化学感受调节的全面结构和机制。xanthus 更广泛的影响。 激发学生对科学和生物化学研究的兴趣对于培养以科学为基础的职业至关重要。 主要研究者将以两种方式让学生在本科生涯的早期就参与进来。 首先，他将设计和实施一个新的实验部分，现有的实验生物化学课程，具有生物物理实验。 这一新颖的部分将补充现有的生物物理学教学课程，并使本科生接触定量方法和生物物理技术。 其次，他将启动一个新的计划，为代表性不足的少数民族学生提供暑期研究机会。 该计划将由RIG赠款和生物化学系资助。 总的来说，这些战略将有助于提供必要的学术和研究背景，以吸引和留住有才华的本科生在科学。