GENETIC AND CHEMICAL STUDIES OF PHAGE LAMBDA DEVELOPMENT

拟议研究的长期目标是了解分子 水平如何指定时间发展途径，如何选择 和基因表达调控机制之间的联系 和位点特异性重组。 温带细菌病毒Lambda 被选为研究这些问题的理想代理人， 一个相对简单的系统，适合生物化学和遗传学的结合 接近。 新补助金的具体目标是学习：（1） 调节事件，其提供了裂解和 病毒发展的溶源途径;（2）负责 位点特异性重组及其定向控制。 工作 溶解或溶原性的转换机制将主要集中在 最近发现的转录后调控的分子基础 涉及Lambda cII、cIII和Int的合成和稳定性 proteins. 实验将使用纯化的病毒和宿主蛋白， 由新旧基因分析指导。 这方面的工作也将 包括与Brian马修斯合作X射线晶体学项目 在俄勒冈州的cII转录调节因子的结构及其 与DNA的相互作用 位点特异性重组的研究将寻求 确定整合和切除重组的分子途径 以及如何控制反应的方向。 纯化的病毒和 将使用宿主蛋白，以及它们与DNA底物的相互作用 详细的探查。 另一项与马修斯的合作研究将试图 确定Int的结构及其与DNA的多种相互作用。

The long term goal of the proposed research is to understand at a molecular level how temporal developmental pathways are specified, how a choice is made between pathways, and the mechanisms for regulation of gene expression and site-specific recombination. The temperate bacterial virus Lambda has been chosen as the ideal agent for a study of these questions in a relatively simple system amenable to combined biochemical and genetic approaches. Specific objectives of the new grant are to learn: (1) the regulatory events that provide for the switch between the lytic and lysogenic pathways of viral development; (2) the mechanisms responsible for site-specific recombination and its directional control. Work on the switch mechanism for lysis or lysogeny will focus primarily on the molecular basis of the recently discovered post-transcriptional controls that involve the synthesis and stability of the Lambda cII, cIII, and Int proteins. The experiments will use purified viral and host proteins, guided by old and new genetic analysis. This aspect of the work will also include a collaborative X-ray crystallography project with Brian Matthews at Oregon on the structure of the cII transcription regulator and its interaction with DNA. The study of site-specific recombination will seek to define the molecular pathways of integrative and excisive recombination and how the direction of the reaction is controlled. Purified viral and host proteins will be used, and their interaction with DNA substrates probed in detail. Another collaborative study with Matthews will try to determine the structure of Int and its multiple interactions with DNA.