F FACTOR-MEDIATED AND OTHER ABORTIVE INFECTIONS

这项研究的主要目的是了解分子 F介导的T7和突变体对T7的限制机制 相关微生物，噬菌体T3。基因和生化研究是 被用来研究多效性生理缺陷 与流产感染有关。这些扰动包括 基因表达，包括转录和翻译，抑制了 噬菌体DNA复制和可能的膜功能障碍。这项工作将 包括对噬菌体基因和染色体或F-质粒的研究 编码的基因决定了F介导的限制。 已恢复能力的突变型T3菌株的假复原体 克服F限制将通过生化手段进行分析研究 主要衣壳蛋白在细胞内的调控作用 转录介导的DNA进入细胞和在早期步骤 噬菌体DNA代谢。这些研究也将并行进行。 用噬菌体T7，以其流产感染的宋内氏志贺菌为原代 生物检测系统。

The primary objective of this research is to understand the molecular mechanisms underlying F-mediated restriction of T7 and of mutants of the related organism, bacteriophage T3. Genetic and biochemical studies are being employed to investigate the pleiotropic physiological defects associated with the abortive infection. These include perturbations in gene expression, both transcriptional and translational, an inhibition of phage DNA replication and possible membrane dysfunctions. The work will include studies both on the phage genes and those chromosomal or F-plasmid encoded genes which determine F-mediated restriction. Pseudorevertants of mutant T3 strains that have regained the ability to overcome F-restriction will be analyzed by biochemical means to investigate the intracellular role of the major capsid protein in controlling the transcriptionally-mediated entry of DNA into the cell and in early steps in phage DNA metabolism. These studies will also be conducted in parallel with phage T7, using its abortive infection of Shigella sonnei as a primary biological assay system.