BACTERIAL CELL MEMBRANE--GROWTH AND CELL DIVISION

细菌细胞膜——生长和细胞分裂

• 批准号: 3284658
• 负责人: MOSELIO SCHAECHTER
• 金额: $ 21.45万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-07-01 至 1992-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3284658
• 关键词: DNA methylation; Escherichia coli; Salmonella typhimurium; bacterial DNA; bacterial genetics; bacterial proteins; bacteriophage lambda; binding proteins; cell cycle; cell growth regulation; cell membrane; density gradient ultracentrifugation; electron microscopy; gel electrophoresis; gene mutation; membrane proteins; membrane structure; microorganism growth; mutant; plasmids; protein biosynthesis; radiotracer; receptor; site directed mutagenesis

Bacteria do not have mitosis but their genome segregates with fidelity during cell division. This is thought to take place by the attachment of DNA to the membrane. In vitro, the replicative origin of the Escherichia coli chromosome (oriC) selectively attaches to membranes when it is hemimethylated at Dam methylase recognition sites, which suggests that segregation is determined by events that are closely tied to initiation of replication. This proposal is to study the nature of this attachment and its cyclical behavior, and to extend the study to plasmids and other bacterial species. The experiments fall into five related areas: 1. Determination of the Dam recognition sites that must be hemimethylated for oriC to bind to membranes. 2. Isolation and characterization of "membrane receptor" proteins. 3. In vivo protein interactions with oriC DNA, studied by treatment of intact cells with dimethyl sulfate. 4. Plasmid Segregation. Do centromere-like sites or other regions of low copy plasmids (F, P1) bind specifically to membranes? Do they encode their own "membrane receptors"? 5. Does hemimethylation play a role in origin-membrane binding in bacteria that do not have Dam methylase?

细菌没有有丝分裂，但它们的基因组与 细胞分裂过程中的保真度。 这被认为发生在 DNA 附着在膜上。 在体外，复制 选择性地选择大肠杆菌染色体 (oriC) 的起源 当它在 Dam 甲基化酶处半甲基化时附着在膜上 识别位点，表明分离已确定 由与复制启动密切相关的事件引起。 这 建议是研究这种依恋的性质及其循环 行为，并将研究扩展到质粒和其他细菌 物种。 这些实验分为五个相关领域： 1. 必须确定的大坝识别地点 半甲基化 oriC 与膜结合。 2.“膜受体”的分离和表征 蛋白质。 3. 体内蛋白质与 oriC DNA 的相互作用，由 用硫酸二甲酯处理完整细胞。 4. 质粒分离。 是否有类似着丝粒的位点或其他区域 低拷贝质粒（F，P1）特异性结合膜？ 它们编码自己的“膜受体”吗？ 5. 半甲基化在原膜结合中起作用吗？ 没有 Dam 甲基化酶的细菌？