Studies on Agrocin 84-a "Trojan Horse" tRNA synthetase inhibitor

智力优势。 大量的微生物次级代谢产物已被证明具有抗菌特性。这些分子的生物学功能可能是复杂的，并反映了微生物参与的高度复杂的关系。该项目的重点是土壤细菌放射性土壤杆菌菌株K84产生的细菌素agrocin 84。农杆菌素84靶向植物病原性细菌根癌农杆菌，其在植物中诱导肿瘤。农杆菌素84是一种分子？特洛伊木马？通过模拟植物肿瘤来源的底物，从而进入细胞内部，在那里它被加工成毒素，TM 84。TM 84是亮氨酰-tRNA合成酶（LeuRS）的有效抑制剂，LeuRS是催化亮氨酸缩合成其同源tRNA并负责遗传密码的正确翻译的必需酶。有趣的是，该毒素的细菌来源放射性土壤杆菌通过具有对TM 84具有抗性的替代合成酶AgnB 2而存活。 本项目的目的是：确定TM 84如何抑制LeuRS，并确定AgnB 2对TM 84耐药性的基础。 这项研究揭示了蛋白质翻译机制的新见解，并扩大了对微生物如何相互作用的理解。该项目的一个主要教育目标是增加代表性不足的少数群体在生物化学领域的参与。这将通过高中和本科生早期接触生物化学科学，实验室研究经验以及通过生物化学领域的讲座，研讨会和实践研究经验的课程指导来实现。研究生培训和指导将贯穿于整个研究和教育计划，以加强专业和科学发展。

Intellectual Merit. A vast number of microbial secondary metabolites have been shown to have antimicrobial properties. The biological functions of these molecules can be complex and reflect the highly complex relationships in which microbes engage. This project focuses on agrocin 84, a bacteriocin, produced by the soil bacterium Agrobacterium radiobacter strain K84. Agrocin 84 targets the plant pathogenic bacterium Agrobacterium tumefaciens, which induces tumors in the plant. Agrocin 84 acts a molecular ?Trojan Horse? by mimicking a plant tumor-derived substrate, and thus gaining access to the interior of the cell, where it is processed into a toxin, TM84. TM84 is a potent inhibitor of leucyl-tRNA synthetase, (LeuRS), an essential enzyme that catalyzes the condensation of a leucine to its cognate tRNA and is responsible for the correct translation of the genetic code. Interestingly, the bacterial source of the toxin, Agrobacterium radiobacter, survives by having an alternative synthetase, AgnB2, that is resistant to TM84. The aims of this project are: to determine how TM84 inhibits LeuRS and to determine the basis for AgnB2 resistance to TM84. The research has the to reveal novel insights into the protein translation machinery and to expand understanding of how microbes interact.Broader Impacts. The project has a major educational goal of increasing underrepresented minority participation in the field of biochemistry. This will be achieved by early exposure of high school and undergraduate students to the science of biochemistry, research experience in the laboratory, and mentorship through programs incorporating lectures, seminars and hands-on research experience in the field of biochemistry. Graduate student training and mentoring will be integrated throughout the research and education plans to enhance professional and scientific development.