Yessinia autotransporters (Yaps): Structure, function, and host response

自转运蛋白（AT）是非常优雅而复杂的蛋白质，理想地定位在细胞膜上。 细菌细胞表面（或释放）与宿主相互作用。AT由三个基本结构域组成： 信号序列、可变大小“过客结构域”（PD）和最后的250-300 在C-末端的氨基酸，其促进PD穿过外膜的易位。虽然 通过计算机模拟分析已经鉴定了1000多个，相对较少的已经详细研究， 它们的分子和生物学功能。Y.鼠疫代表了一种极好的 机会这样做，因为（a）他们似乎并不密切相关的已经研究的AT，因此， 可能编码新的功能，和（B）Y.鼠疫可以通过分子、遗传和生物学手段 问题研究我们有初步的数据表明，所有10个yap在感染过程中表达。我们也 表明，大多数的Yaps是本地化和暴露在细菌表面，而其他的 似乎被释放到培养物上清液中。此外，我们在所有的基因组中构建了缺失突变， 在一个完全致命的Y染色体中的十个废话中。鼠疫菌株，并已开始测试这些突变的影响， 毒性虽然这些测试正在进行中，但其中四个突变体显然具有腺鼠疫的表型 感染的模式。这些结果与我们的假设一致，即雅普人在 发病机制本研究旨在探讨寄主对Y.鼠疫和雅普人在 这些应答（目的1和2）是基于观察到许多雅普突变似乎影响早期 和/或传播的Y.鼠疫这些研究不仅能告诉我们关键的宿主反应， 在Y.鼠疫感染，但他们也应该给我们重要的线索，作为主机的目标雅普人。这 我将补充目标3中描述的结构工作，目的是定义蛋白质的重要功能结构域。 Yaps，并为将来筛选广谱小分子抑制剂提供基础。 AT

Autotransporter proteins (ATs) are exceptionally elegant yet complex proteins ideally positioned on the bacterial cell surface (or released) for interactions with the host. ATs consist of three basic domains: a Nterminal signal sequence, a "passenger domain" (PD) of variable size and finally a (3-domain of 250-300 amino acids at the C-terminus that facilitates translocation of the PD across the outer membrane. Although more than 1000 have been identified by in silico analyses a relatively few have been studied in detail as to their molecular and biological function. The Yaps (predicted ATs) of Y. pestis represent an excellent opportunity to do this as (a) they do not appear to be closely related to the already well studied ATs and thus are likely to encode novel functions, and (b) Y. pestis is amenable to molecular, genetic and biological studies. We have, preliminary data indicating that all ten of the yaps are expressed during infection. We also demonstrated that most of the Yaps are localized and exposed on the bacterial surface, while the others appear to be released into the culture supernatant. In addition, we have constructed deletion mutations in all of the ten yaps in a fully virulent Y. pestis strain and have begun testing the effect of these mutations on virulence. While these tests are ongoing, four of these mutants clearly have phenotypes in a bubonic plague model of infection. These results are consistent with our hypothesis that the yaps play a role in pathogenesis. The studies proposed here to examine the host response to Y. pestis and the role of Yaps in hat response (Aims 1 & 2) are based on the observation that many yap mutations appear to affect early vents and/or dissemination of Y. pestis. These studies should inform us not only about key host responses during Y. pestis infection, but they should also give us important clues as to host targets of the Yaps. This ll complement the structural work described in Aim 3 aimed at defining important functional domains of the Yaps and also at providing a foundation for future screening for broad spectrum small molecule inhibitors of ATs.