PHOSPHOLIPID METHYLTRANSFERASE IN S CEREVISAE & S POMBE

我们研究了A蛋白的结构、功能、免疫学和遗传学。 一大类相关蛋白，细菌菌毛。Pili是 由相同的蛋白质分子(菌毛蛋白)组成的棒状集合。一些人 各种菌毛都有顶端附着的结构，由 分化的菌毛蛋白(粘连和其他次要蛋白)。这个 菌毛的主要功能是将细菌附着在特定的(通常是 碳水化合物)受体在宿主细胞上。这个的Pilus站点 粘连位于其远端。基本上所有的病原体 细菌表达菌毛。细菌的组织器官嗜性 病原体在很大程度上是由它们的结合特异性决定的 菌毛及其受体在寄主中的分布。这个 我们的研究目标是基础性的和应用性的。我们寻求 了解菌毛内和菌毛之间的结构-功能关系 分子尺度。为此，我们测定了氨基酸 用化学和化学方法测定大量菌毛蛋白序列 基因技术。我们还确定了 用X射线衍射法和结晶学研究菌毛中的蛋白质亚基 技巧。通过比对一些氨基酸序列 我们有不同的菌毛、粘连和其他菌毛蛋白 发现了一个庞大的相关菌毛超家族，我们称之为‘’菌毛 超级家庭I‘’。这个家族包括来自许多重要的 病原体，例如：大肠杆菌、伤寒沙门氏菌、 肺炎克雷伯菌、粘质沙雷氏菌和嗜血杆菌 流感病毒。这些序列的比对揭示了保守的 参与常见多肽折叠和蛋白质的超家族序列 装配模式，保守的粘附性家族序列 与菌毛受体结合，以及参与的可变序列 菌毛间结合和/或抗原变异作为一种免疫逃避 机制。

We study the structure, function, immunology and genetics of a large class of the related proteins, bacterial pili. Pili are rod-like assemblies of identical protein molecules (pilins). Some kinds of pili have tip-attached structures consisting of differentiated pilins (adhesions and other minor proteins). The principal function of pili is to attach bacteria to specific (usually carbohydrate) receptors on host cells. The pilus site for this adhesion is located on their distal tip. Essentially all pathogenic bacteria express pili. The tissue and organ tropisms of bacterial pathogens is largely determined by the binding specificity of their pili and the distribution of pilus receptors in the host. The objectives of our research are fundamental and applied. We seek to understand the structure-function relationships in and among pili on a molecular scale. To this end we have determined the amino acid sequences of a large number of pilus proteins using both chemical and genetic techniques. We have also determined the arrangement of protein subunits in pili using X-ray diffraction and crystallographic techniques. By aligning the amino acid sequences of a number of different pilins, adhesions and other pilus proteins we have discovered a large superfamily of related pili we call ``pilus superfamily I''. This family includes pili from a number of important pathogens, for example: Escherichia coli, Salmonella typhi, Klebsiella pneumoniae, Serratia marscescens, and Hemophilus influenzae. The alignment of these sequences has revealed conserved superfamily sequences involved in common peptide folding and protein assembly patterns, conserved adhesion family sequences invol ved in binding to pilus receptors, and variable sequences involved in inter-pilus binding and/or antigenic variation as an immune evasion mechanism.