MOLECULAR BIOLOGICAL CHARACTERIZATION OF ORAL BACTERIA

口腔细菌的分子生物学特征

• 批准号: 3917059
• 负责人: B M CHASSY
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DENTAL & CRANIOFACIAL RESEARCH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3917059
• 关键词: Bacillus subtilis; Escherichia coli; Lactobacillaceae; Lactobacillus casei; Salmonella typhimurium; Staphylococcus aureus; Streptococcus lactis; bacterial DNA; bacterial genetics; bacterial proteins; electroporation; gene expression; gene therapy; genetic manipulation; genetic regulation; host organism interaction; lac operon; molecular cloning; mutant; nucleic acid sequence; oral bacteria; plasmids; virulence

This project seeks to use genetic, biochemical and physiological approaches to investigate the pathogenicity of oral bacteria. The two specific areas of investigation are: 1) characterization of plasmid-coded and chromosomal metabolic genes from oral bacteria and 2) development of systems for genetic exchange in oral bacteria. The nucleotide sequence of the EnzymeIIlac gene of Lactobacillus casei was completed. It displayed high homology to the same genes isolated from staphylococcus aureus and Streptococcus lactis. Little homology was observed in comparison with other EnzymeII found in Escherichia coli, Salmonella typhimurium or Bacillus subtilis. The genes encoding the EnzymeIIlac, P-beta-gal and Factor IIlac were found to comprise an operon-like structure. Site-directed mutagenesis has been used to prepare mutant EnzymeII proteins with altered catalytic activity. The sequence of the plasmid-coded beta-galactosidase of Lactobacillus casei has been completed: the adjacent lac permease gene has been cloned and its sequence is being determined. L. casei has been utilized for the cloning and expression of heterologous genes such as alpha-amylase, subtilisin and beta-gal. Expression and secretion of foreign proteins has been observed; improved vectors and promoters have been identified. Using electroporation, L. bulgaricus and L. acidophilus have been transformed. The feasibility of use of these food related bacteria that colonize the gastrointestinal system as vectors for gene delivery to humans is being examined.

该项目旨在利用遗传、生化和生理学 研究口腔细菌致病性的方法。 研究的两个具体领域是：1）表征 口腔细菌的质粒编码基因和染色体代谢基因 2) 口腔遗传交换系统的开发 细菌。 EnzymeIIlac基因的核苷酸序列 干酪乳杆菌完成。 表现出高度的同源性 从金黄色葡萄球菌中分离出相同的基因 乳酸链球菌。 比较中观察到很少有同源性 与大肠杆菌、沙门氏菌中发现的其他酶 II 一起使用 鼠伤寒杆菌或枯草芽孢杆菌。 编码基因 发现 EnzymeIIlac、P-β-gal 和 Factor IIlac 包含 类似操纵子的结构。 定点诱变已被用于 制备具有改变的催化活性的突变酶II蛋白。 质粒编码的β-半乳糖苷酶的序列 干酪乳杆菌已完成：邻近的紫胶渗透酶 基因已被克隆，其序列正在确定。 L。 干酪已被用于克隆和表达 异源基因，例如α-淀粉酶、枯草杆菌蛋白酶和β-gal。 已观察到外源蛋白的表达和分泌； 已鉴定出改进的载体和启动子。 使用 电穿孔，保加利亚乳杆菌和嗜酸乳杆菌 转变了。 使用这些食品相关细菌的可行性 作为基因载体定植胃肠系统 正在检查向人类的交付。