PHOSPHOLIPID METHYLTRANSFERASE IN S CEREVISAE & S POMBE

我们研究了一种具有免疫学和遗传学功能的 细菌皮利是一大类相关蛋白质。 皮利是 由相同蛋白质分子（菌毛蛋白）组成的棒状集合体。 一些 20种皮利具有尖端附着结构， 分化的菌毛蛋白（粘附和其他次要蛋白质）。 的 皮利的主要功能是将细菌附着在特定的（通常 碳水化合物）受体。 菌毛部位 粘附位于它们的远侧尖端上。 基本上所有致病性 细菌表达皮利。 细菌的组织和器官嗜性 病原体在很大程度上是由它们的结合特异性决定的。 皮利和菌毛受体在宿主体内的分布。 的 我们的研究目标是基础性和应用性的。 我们寻求 了解结构和功能之间的关系皮利上 分子尺度 为此，我们确定了氨基酸 大量菌毛蛋白的序列， 基因技术 我们还决定安排 皮利中蛋白质亚基的X-射线衍射和晶体学分析 技术. 通过比对一些人的氨基酸序列， 不同的菌毛蛋白，粘连蛋白和其他菌毛蛋白， 我发现了一个大的超家族的相关皮利，我们称之为“菌毛 超家族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、粘质沙雷菌和嗜血杆菌 流感。 这些序列的比对揭示了保守的 参与常见肽折叠和蛋白质的超家族序列 组装模式、保守的粘附家族序列参与其中 与菌毛受体的结合，以及参与 菌毛间结合和/或抗原变异作为免疫逃避 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.