CONTROL OF VIRUS-INDUCED LYSIS

探索、检测和修改细胞蛋白质特征的能力 表面是许多诊断性和非接触性的长期发展的关键 治疗策略。一个主要的障碍是， 蛋白质-膜相互作用的基本性质在很大程度上是未知的。 噬菌体裂解属可能构成一个强大的模式系统 制定蛋白质膜的物理和生化规律 互动。两个原型裂解基因是噬菌体S基因 PhiX174E基因及相应的单链环状DNA噬菌体。 这些基因很小(通常少于或等于100个密码子) 编码无酶活性。相反，的主要功能是 这些基因的产物是嵌入到膜中并导致形成的 致命的膜孔。这些基因既可能是阳性，也可能是 和实验室中的负选择压力，并服从于 快速序列分析。突变研究旨在确定 对于薄膜嵌入来说很重要，已经进行并将 扩大了。此外，基因融合技术将被应用于 用于直接生化的大量蛋白质的纯化 使用人工蛋白脂质体进行分析。此外，分子基础也是 在感染周期结束时安排裂解的“时钟”将 通过基因和重组DNA的组合进行研究 方法论。S基因编码两种产物，其中一种是 抑制物和另一个是裂解的效应物，这些蛋白质不同 仅在氨基末端，由于在两个点的翻译开始 不同的起始码。对裂解的调节至少部分取决于 关于核糖体获得这两个起始密码子的调节，并可能 涉及宿主蛋白与S基因的结合。这些蛋白质是 这一调节将被识别并分配给一个细菌基因。 此外，宿主基因slyD是形成裂解孔所必需的 PhiX174 E蛋白的功能和相互作用 通过细胞分裂过程。

The ability to explore, detect and modify the protein features of cell surfaces is a key in the long-term development of many diagnostic and therapeutic strategies. A major obstacle is the fact that the fundamental nature of protein-membrane interactions is largely unknown. Bacteriophage lysis genus may constitute a powerful model system for working out the physical and biochemical rules of protein-membrane interactions. Two prototype lysis genes are the S gene of lambdoid phage and the E gene of phiXl74 and related single-stranded circular DNA phage. These genes are small (typically less than or equal to 100 codons) and encode no enzymatic activity. Instead, the primary function of the products of these genes is to imbed in membranes and cause the formation of lethal membrane holes. These genes can be subjected to both positive and negative selective pressure in the laboratory and are amenable to quick sequence analysis. Mutational studies designed to determine what is important for membrane imbedding have been conducted and will be expanded. Moreover, gene fusion technology will be employed to allow purification of quantities of these proteins for direct biochemical analysis using artificial proteoliposomes. Also, the molecular basis of the "clock" which schedules lysis at the end of the infective cycle will be investigated by a combination of genetic and recombinant DNA methodologies. The S gene encodes two products, one of which is an inhibitor and the other an effector of lysis, and these proteins differ only at the amino-terminus, as a result of translation initiations at two different start codons. The regulation of lysis depends at least in part on the regulation of ribosome access to these two start codons and may involve the binding of host proteins to the S mRNA. The proteins for this regulation will be identified and assigned to a bacterial gene. Also, the host gene slyD required for the formation of lysis holes by the phiX174 E protein will be characterized as to function and interaction with cell division processes.