WHOLE GENOME PHAGE DISPLAY OF T PALLIDUM GENES

许多基因的功能不能从序列相似性推断，通常需要生物化学方法。 全基因组序列可以被认为不仅是一组基因，而且是功能域的集合。 这些结构域可以通过亲和方法进行研究，由此配体的鉴定可以提供关于生物化学功能的信息。 为了利用这种方法，必须以适合亲和力研究的形式表达所有功能结构域。 噬菌体展示技术提供了实现这一点的手段。 将构建包括梅毒螺旋体的所有开放阅读框（ORF）的噬菌体展示文库。 t.梅毒是梅毒的病原体。 这种生物体的完整基因组序列最近已经完成。 T. pallidum使其成为开发和测试基因组噬菌体展示技术的优良系统。 首先，基因组的大小为100万个碱基对，是已知最小的基因组之一。第二，总共有1041个开放阅读框架，这使得在相对短的时间内系统地构建包含每个ORF的文库是可行的。 最后，由于没有连续培养系统，因此对该生物体的生物学或致病机理知之甚少。 这严重限制了生物体研究的实验选择。 因此，需要新的方法来了解T.苍白球 将构建两种类型的噬菌体展示文库。 通过系统地插入T. pallidum转化到噬菌体展示载体中。 第二个文库将通过随机片段化的T.苍白球基因组DNA。该文库将用于鉴定参与T.苍白球与纤连蛋白和宿主细胞的结合。 此外，该文库还将用于鉴定T. pallidum DNA结合蛋白并定位其结合位点。 这些信息可以用来发现T.苍白球转录调控网络。 这项工作也将作为一个模型系统，使用基因组噬菌体展示作为功能基因组学的工具。

The function of many genes cannot be deduced from sequence similiarity, and biochemical methods are usually required. Whole genome sequences can be thought of as not only a set of genes but also collections of functional domains. These domains can be studied by affinity methods whereby identification of the ligand can provide information on biochemical function. To take advantage of this method, one must express all functional domains in a form suitable for affinity studies. Phage display technology provides a means for accomplishing this. Phage display libraries that include all of the open reading frames (ORFs) of Treponema pallidum will be constructed. T. pallidum is the causative agent of syphilis. The complete genome sequence of this organism has recently been completed. Several features of T. pallidum make it an excellent system on which to develop and test genomic phage display technology. First, with a size of 1 million base pairs, the genome is one of the smallest known. Second, there are a total of 1041 open reading frames which makes it feasible to systematically construct libraries containing each ORF in a relatively short period of time. Finally, little is known of the biology or pathogensis of this organism because a continuous culture system is not available. This severely limits the experimental options for study of the organism. Therefore, new approaches are needed to understand gene function in T. pallidum. Two types of phage display libraries will be constructed. One type will be constructed by systematically inserting each of the 1041 ORFs of T. pallidum into a phage display vector. The second library will be constructed by shotgun cloning of randomly fragmented T. pallidum genomic DNA. The libraries will be used to identify ORFs that are involved in attachment of T. pallidum to fibronectin and host cells. In addition, the libraries will be used to identify T. pallidum DNA binding proteins and locate their binding sites. This information can be used to discover T. pallidum transcriptonal regulatory networks. The work will also serve as a model system for the use of genomic phage display as a tool for functional genomics.