VIRUS CHROMOSOME STRUCTURE: ROLE IN DEVELOPMENT

我们正在研究病毒的形态发生，使用噬菌体伽马作为模型。 系统。我们的工作集中在几个病毒组装步骤上，处理 尤其是DNA包装。病毒组装的第一个方面是我们 研究的是基因组识别。所有的病毒都面临着 从一种核酸中封装病毒染色体。这位将军 解决这个问题的办法是该病毒产生一种识别蛋白 它专门与病毒基因组结合。对于伽马来说，识别是 通过终止酶的作用完成，病毒DNA包装 酵素。终端酶与伽马DNA上的一个位点(Cosb)特异性结合，并与 前部是空的蛋白质壳，DNA被包装在里面。我们是 对终止酶与HE DNA的相互作用感兴趣 前锋。第二个方面是DNA处理。许多病毒都会产生 后代DNA是被切割成单位长度的线性聚合物的形式 在包装过程中。对于伽马来说，DNA处理也是功能之一 在CoSN，它引入交错的缺口，以生成 在病毒DNA分子上发现的粘性末端。第三个方面是 组装过程中蛋白质有序相互作用的分子基础。 病毒结构，如衣壳，是按顺序生产的 反应的结果。在许多情况下，例如对于噬菌体T4尾巴， 集合的顺序已经安排得很好了。一般的解释是如何 反应的顺序是受控的，当一个亚单位 在生长的结构上增加，形成反应部位以结合 Next组件，该组件进而为下一个 亚单位。人们对亚基-亚基之间的相互作用知之甚少。 分子水平。终端酶结合前头，显然是激活的 我们已经开始了这样的研究。第四，对于具有 溶源(或潜伏)循环。我们曾遇到过这样的情况 对终止酶表达的调节明显被打乱， 导致潜在溶原物的损失。看起来很紧 对终止酶表达的控制，而不是抑制，以及 目前正在对这些文件进行审查。第四，将伽马DNA注射到宿主体内 细胞没有被很好地理解。有证据表明，特定的DNA： 蛋白质相互作用对注射很重要，因为注射是 对于DNA分子来说非常糟糕，因为DNA分子有取代 正常的染色体右端。我们已经分离出一种影响 注射，因此可以开始详细的研究。

We are studying virus morphogenesis, using bacteriophage gamma as a model system. Our work focusses on several virus assembly steps, dealing especially with DNA packaging. The first aspect of virus assembly we are studying is genome recognition. All viruses face the problem of encapsidating the virus chromosome from a nucleic acids. The general solution to the problem is that the virus produces a recognition protein that specifically binds to the viral genome. For gamma, recognition is accomplished through the action of terminase, the viral DNA packaging enzyme. Terminase specifically binds to a site (cosB) on gamma DNA and to the prohead, the empty protein shell into which DNA is packaged. We are interested in the interaction of terminase with both he DNA and the prohead. The second aspect is DNA processing. Many viruses produce progeny DNA is the form of linear polymers that are cut to unit length during packaging. For gamma,DNA processing is also one of the functions of terminase, which introduces staggered nicks, at cosN, to generate the cohesive ends found on virion DNA molecules. The third aspect is the molecular basis for ordered protein-protein interactions during assembly. Viral structures, such as the capsid, are produced in an ordered series of reactions. In a number of cases, such as for the phage T4 tail, the order of assembly is well worked out. The general explanation for how sequential ordering of reactions is controlled is that when a subunit adds to a growing structure, a reactive site is formed for binding the next component, which in turn generates a binding site for the next subunit. Little is known about these subunit-subunit interactions at the molecular level. Terminase binds the prohead, and apparently is activated to do so and we have begun such a study. Fourth, for viruses that have a lysogenic (or latent) cycle. We have encountered situations in which regulation of the expression of terminase is apparently disrupted, leading to the loss of potential lysogens. It appears that are tight controls on the expression of terminase quite apart from repression, and these are being examined. Firth, injection of gamma DNA into the host cell is not well understood. There exists evidence that specific DNA: protein interactions are important for injection, because injection is very poor for DNA molecules that have a substitution that replaces the normal right chromosomal end. We have isolated a point mutation affecting injection and can therefore begin detailed studies.