MOLECULAR BIOLOGICAL CHARACTERIZATION OF ORAL BACTERIA

口腔细菌的分子生物学特征

• 批准号: 4692590
• 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/4692590
• 关键词: 6 phosphofructokinase; Lactobacillus casei; Streptococcus lactis; Streptococcus mutans; Streptococcus sanguis; bacterial DNA; beta fructofuranosidase; carbohydrate metabolism; carbohydrate transport; cell fusion; dental caries; endonuclease; evolution; exoenzyme; genetic library; genetic regulation; genetic transcription; glucokinase; glycosyltransferase; lactose; microorganism immunology; molecular biology; oral bacteria; plasmids; sucrose; surface antigens; virus genetics

This project seeks to use genetic, biochemical and physiological approaches to investigate the pathogenicity of oral bacteria. The three specific areas of investigation are: 1) molecular cloning and characterization of genes encoding surface structures that mediate attachment of oral microbes, 2) characterization of plasmid-coded and chromosomal metabolic genes from oral bacteria and 3) development of systems for genetic exchange in oral bacteria. A gene encoding the structural subunit of the Type 2 fimbriae of Actinomyces viscosus was cloned into Escherichia coli using the cosmid vector pHC79. This has was subcloned into p&C13 on a 10 Kbp HIND III fragment; the clone expresses the complete 59 Kdal fimbrial subunit. Subcloning for M13 dideoxy sequencing is now in progress. A gene encoding the synthesis of the Type 1 fimbriae was identified in a second genomic library; its sequence is under study. The gene for the Type 2 fimbriae of A. naeslundii was also cloned; it was found to share DNA-DNA homology with the gene isolated from A. viscosus. An unusual plasmid encoding the enzyme Beta-galactosidase was found in L. actobacillus casei; the structural gene was cloned into E. coli using the plasmid expression vector pKK223-3. Subclones are being prepared for sequencing and for analysis of L. casei promoter structure and function. For the first time Lactobacillus strains were transformed; using lactose plasmids encapsulated in liposomes prepared from lecithin, lactose fermenting transformants were derived from lactose negative strains of L. casei. Southern blot analysis confirmed the introduction of specific lactose metabolic genes into the L. casei chromosome. Current studies seek to optimize and improve the transformation system.

该项目试图使用遗传，生化和生理方法 研究口服细菌的致病性。 这三个具体 研究领域是：1）分子克隆和表征 编码介导口服微生物附着的表面结构的基因， 2）从质粒编码和染色体代谢基因的表征 口服细菌和3）开发口服遗传交换的系统 细菌。 一个编码2型纤维化的结构亚基的基因 使用宇宙将放线肌粘膜克隆到大肠杆菌中 向量PHC79。 在10 kbp Hind III上，这已被亚克隆到P＆C13中 分段;克隆表达完整的59 kDal纤维亚基。 现在正在进行M13 Dideoxy测序的亚克隆。 一个基因编码 在第二个基因组中鉴定出1型纤维状的合成 图书馆;它的序列正在研究。 2型纤维化的基因 A. naeslundii也被克隆了。发现它可以与 从粘曲霉分离的基因。 编码酶的异常质粒 β-半乳糖苷酶在甲状腺乳杆菌乳杆菌中发现；结构基因 使用质粒表达载体PKK223-3克隆到大肠杆菌中。 正在为测序和分析Casei的测序准备子克隆 启动子结构和功能。 首次乳杆菌菌株 被转变了；使用包裹在制备的脂质体中的乳糖质粒 从卵磷脂中，乳糖发酵转化体是从乳糖中得出的 L. casei的负菌株。 Southern印迹分析证实了 将特定的乳糖代谢基因引入酪液。 染色体。 当前的研究旨在优化和改善 转换系统。