Present and Potential Functions of Bacterial Transporters

细菌转运蛋白的当前和潜在功能

• 批准号: 0847465
• 负责人: L.Nicholas Ornston
• 金额: $ 30万
• 依托单位: Yale University
• 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 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0847465&HistoricalAwards=false
• 关键词: Present; Potential; Functions; Bacterial; Transporters

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Intellectual merit. The project will test the hypothesis that nutrient transporters possess functional versatility and genetic malleability that allow them to serve as wedges in the evolutionary divergence of bacteria. Individual transporter genes will be studied in bacteria in which all transporters with overlapping or potentially overlapping activities have been deleted. The properties conferred by each transporter will then be determined. Mutant genes that confer altered growth phenotypes will be selected, and these genes will be sequenced to determine amino acid sequence substitutions that caused the change in transporter activity. This work will be conducted with Acinetobacter baylyi, a bacterium that offers singular advantages for genetic investigation because of its nutritional breadth and its extraordinarily high competence for natural transformation. In the future, genetic constructs in A. baylyi will allow the procedures to be adapted to determine the functions of transporters from other bacteria, including those with complex genomes or those that are difficult to grow.A central question in bacteriology is what makes an organism stand apart? Obvious sources of differences are in genomes where gene rearrangements mark discontinuities in the evolutionary divergence of cell lines. Less obvious, but perhaps as significant, are differences in activities, such as transmembrane transport, that determine how a cell adapts to an often shifting environment. Transmembrane transporters are well suited for accommodating evolutionary divergence because they are poised to have direct contact with the environment, they are abundant (frequently encoded by genes accounting for 10% or more of a genome), and they possess a redundancy that may allow one transporter to maintain an activity while another transporter with overlapping function adapts to a new challenge. To understand the extent to which transporters contribute to evolutionary divergence depends upon knowledge about both their functions and the genetic simplicity with which they can shift from one activity to another. Present information, based upon an overwhelming amount of genome sequence data, provides only a glimpse of the necessary knowledge because sequence similarities are poor predictors of similarities in transporter function. This project is designed to develop a system for learning how a major subset of transporters contributes to physiology and potential genetic adaptation in A. baylyi. A merit of the system is that it will provide a foundation for study of genes easily cloned from other bacteria.Broader impacts. The project will have a broad impact on scientific training and research. Yale graduate students on rotation through the lab and undergraduates will participate in the research. The A. baylyi genetic system is the basis for teaching laboratories around the world because natural transformation provides a swift demonstration of what a gene is and what it does. Support for this research program will facilitate the continued supply of bacterial strains for introductory college teaching and to create upper level teaching laboratories on the genetic analysis of transport. Key research findings will be integrated into classes at local high schools as part of the Yale Outreach Program. Funding will allow further participation in the Yale SURF summer research program, which introduces minority undergraduate students to investigative science. Results of the research will be disseminated through presentations at national meetings and the scientific literature. Bacterial strains will assist other laboratories in cloning and characterizing other genes for bacterial transporters and will thereby provide a useful resource for further research in the scientific community. Results from the project are likely not only to give insight into a basic question of transporter evolution, that is how substrate specificity evolves, but also to provide a knowledge base that will contribute to bioremediation and biotechnological applications, both of which depend upon transport and processing of metabolites.

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)资助的。该项目将测试营养转运体具有功能多功能性和遗传延展性的假设，这使得它们能够在细菌的进化分歧中充当楔子。将在细菌中研究单个转运蛋白基因，在这些细菌中，所有具有重叠或潜在重叠活性的转运蛋白都已缺失。然后将确定每个传送器授予的属性。将选择导致生长表型改变的突变基因，并对这些基因进行测序，以确定导致转运蛋白活性变化的氨基酸序列替换。这项工作将与贝利不动杆菌进行，这是一种细菌，由于其营养广度和极高的自然转化能力，为遗传学研究提供了独特的优势。在未来，贝利螺旋藻的基因结构将允许对程序进行调整，以确定来自其他细菌的转运蛋白的功能，包括那些具有复杂基因组的细菌或那些难以生长的细菌。细菌学的一个中心问题是，是什么让生物体与众不同？差异的明显来源是基因组，在基因组中，基因重排标志着细胞系进化分歧的中断。不那么明显，但可能同样重要的是活动的差异，例如跨膜运输，这决定了细胞如何适应经常变化的环境。跨膜转运体非常适合于适应进化的差异，因为它们准备与环境直接接触，它们丰富(通常由占基因组10%或更多的基因编码)，它们具有冗余，可能允许一个转运体保持活动，而另一个具有重叠功能的转运体适应新的挑战。要了解转运蛋白对进化分化的贡献程度，取决于对它们功能的了解，以及它们可以从一种活动转移到另一种活动的遗传简单性。目前的信息基于大量的基因组序列数据，只提供了必要知识的一瞥，因为序列相似性不能很好地预测转运蛋白功能的相似性。这个项目的目的是开发一个系统，以了解转运蛋白的主要子集如何对杨柳条的生理和潜在的遗传适应做出贡献。该系统的一个优点是它将为研究从其他细菌中容易克隆的基因提供基础。该项目将对科学培训和研究产生广泛影响。耶鲁大学的研究生和本科生将轮流参加这项研究。A.baylyi基因系统是世界各地教学实验室的基础，因为自然转化提供了快速演示什么是基因以及它的功能。对这项研究计划的支持将有助于继续为大学入门教学提供细菌菌株，并创建关于运输遗传分析的高级教学实验室。作为耶鲁推广计划的一部分，关键研究成果将被整合到当地高中的课堂上。资金将允许进一步参与耶鲁大学冲浪暑期研究项目，该项目向少数族裔本科生介绍调查科学。研究结果将通过在国家会议上的陈述和科学文献来传播。细菌菌株将协助其他实验室克隆和鉴定细菌转运蛋白的其他基因，从而为科学界的进一步研究提供有用的资源。该项目的结果不仅可能深入了解转运体进化的一个基本问题，即底物专一性如何进化，而且还可能提供一个有助于生物修复和生物技术应用的知识库，这两者都依赖于代谢物的运输和加工。