Degradative Plasmids: Comparative Regulatory Sequences

降解质粒：比较调控序列

• 批准号: 9100015
• 负责人: Ananda Chakrabarty
• 金额: $ 34.5万
• 依托单位: University of Illinois at Chicago
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-08-15 至 1996-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9100015&HistoricalAwards=false
• 关键词: Degradative; Plasmids; Comparative; Regulatory; Sequences

Highly chlorinated compounds have been manufactured by the chemical industry for several decades now, resulting in their release into the environment. While simple chlorinated compounds are biodegradable, highly chlorinated compounds are quite persistent due to limited breakdown by natural microflora which reflects the absence of degradative genes against such compounds in these microorganisms. We have thus been interested in understanding how new genes encoding degradation of simple chlorinated compounds evolve in nature with the hope that such understanding may help us to accelerate the process of evolution in a laboratory setting against highly chlorinated compounds. Three structural genes encoding the degradative enzymes of 3 chlorocatechol and a regulatory gene that regulates positively the expression of the three structural genes, have been mapped on a plasmid pAC27 in a main strain of Pseudomonas putida as an operon ( the clc operon), similar to another set of chromosomal genes that allow degradation by P. putida of the natural parent compound, catechol ( the cat operon). This grant seeks to determine how the products of the regulatory genes catR and clcR bind with the operator/promoter regions of the two operons catBC and clcABD to allow transcription of these two operons in presence of the inducers cis, cis-muconate and 2 chloro-cis, cis-muconate. Since the genetic organization of the two operons is quite similar, and the individual genes of these two operons demonstrate extensive homology, it is important to understand how genes for a regulated pathway, which includes a chlorinated compound as an inducer, evolve from ancestral genes that encode dissimilation of an analogous non-chlorinated compound. The molecular details of specific nucleotides in the catBC and clcABD operator/promoter regions that are involved in the binding with CatR and ClcR in presence of the non-chlorinated and chlorinated muconates as well as the amino acids of the regulatory proteins CatR and ClcR that are involved in specific base contacts in the operator/promoter region, will provide considerable insight regarding the mechanism of evolution of regulatory systems in response to the release of chlorinated compounds.

这种化学品制造了高氯化物 几十年来，他们一直在努力， 环境保护 虽然简单的氯化物 可生物降解的高氯化物是相当持久的 由于自然微生物菌群的有限分解， 在这些细胞中不存在针对这些化合物的降解基因， 微生物的 因此，我们有兴趣了解如何 编码简单氯化物降解的新基因 在自然界中进化，希望这种理解可以帮助我们 在实验室环境中加速进化过程 对抗高氯化物 三个结构基因 编码3-氯邻苯二酚和 调节基因，其积极调节 三个结构基因，已被定位在质粒pAC 27上， 恶臭假单胞菌的主要菌株作为操纵子（clc操纵子）， 类似于另一组允许降解的染色体基因 由恶臭假单胞菌的天然母体化合物儿茶酚（猫 操纵子）。 这项补助金旨在确定如何产品的 调节基因catR和clcR与操纵子/启动子结合 两个操纵子catBC和clcABD的区域，以允许转录 这两个操纵子在诱导剂顺，顺-粘康酸存在下 和2-氯-顺，顺-粘康酸酯。 由于遗传组织的 这两个操纵子是非常相似的， 两个操纵子表现出广泛的同源性，重要的是 了解基因如何调控途径，其中包括 氯化物作为诱导物，从祖先基因进化而来 编码一种类似的非氯化化合物的异化。 catBC中特定核苷酸的分子细节和 clcABD操纵子/启动子区参与结合 与CatR和ClcR在非氯化和 氯化粘康酸盐以及调节氨基酸 参与特异性碱基接触的蛋白质CatR和ClcR 在操纵子/启动子区域，将提供相当多的见解 关于监管制度的演变机制， 对氯化物释放的反应。