STRUCTURAL STUDIES OF INNER KINETOCHORE PROTEIN COMPLEXES FROM BUDDING YEAST

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 其目标是确定发芽酵母内部动粒成分的结构，长期目标是创建动粒分子组织的完整图景。在发芽酵母的情况下，内部着丝粒的成分--即与着丝粒DNA直接或非常密切相关的蛋白质--包括着丝粒结合因子1和3(CBF1和CBF3)、Mif2和Mif2，在Mif2中，H3被着丝粒特有的组蛋白Cse4取代(在人类中为CENP-A)，以及核小体组装因子Scm3。在2009年期间，我们确定了CBF3的主要组成部分Ndc10的结构。在2010年，我们已经确定了Cse4核小体的组装状态的结构：Cse4，H4和ScM3片段的三向复合体(在2.3？分辨率)和Cse4：H4异四聚体(在2.6？分辨率)。这两种结构有助于我们对动粒组装途径的理解。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The goal is to determine the structures of components of the budding-yeast inner kinetochore, with the longer-term objective of creating a complete picture of kinetochore molecular organization. In the case of budding yeast, the components of the inner kinetochore -- that is, the proteins directly or very closely associated with centromeric DNA -- include centromere-binding factors 1 and 3 (Cbf1 and CBF3), Mif2, a "specialized" nucleosome in which H3 is replaced by a centromere-specific histone known as Cse4 (CENP-A in humans), and a nucleosome assembly factor, Scm3. During 2009, we determined the structure of Ndc10, a major component of CBF3. During 2010, we have determined structures of assembly states of the Cse4 nucleosome: a three-way complex of Cse4, H4, and a fragment of Scm3 (at 2.3 ¿ resolution) and a Cse4:H4 heterotetramer (at 2.6 ¿ resolution). The two structures contribute to our growing understanding of pathways of kinetochore assembly.