COORDINATING REPAIR: SAXS ANALYSIS OF XRCC1 BASE EXCISION REPAIR COMPLEXES

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。 我们的实验室对了解参与细胞DNA交易的蛋白质感兴趣。具体地说，我们试图通过使用结构生物学技术如核磁共振、X射线结晶学和小角X射线散射来阐明允许DNA修复/复制中间体有效地转移到后续结合伙伴的机制。在Bio-CAT光束线上进行的小角X射线散射实验旨在研究一系列与修复受损DNA有关的蛋白质：蛋白质和蛋白质：DNA复合体。在整个赠款周期中分配的一天的光束时间使我们能够对这些复合体进行初步表征；计划进行更多的实验来跟进我们的初步结果，而光束时间的分配是限制因素。除了我们的DNA修复项目外，SAXS还收集了与肺炎感染有关的DNA内切酶的数据。这些数据导致了一本描述我们对这种蛋白质的生化和生物物理分析的单一出版物。在Bio-CAT收集的SAXS数据可以确定这种蛋白质的化学计量比，这在以前是有争议的，因为这个家族的其他成员是已知的二聚体。此外，还生成了从头算模型，允许将基于SAXS的包络模型与同源晶体结构进行比较。

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. Our lab is interested in understanding proteins involved in cellular DNA transactions. Specifically, we attempt to elucidate the mechanisms that allow for efficient transfer of DNA repair/replication intermediates to subsequent binding partners through the use of structural biology techniques such as NMR, X-ray crystallography and small-angle X-ray scattering. Small-angle X-ray scattering experiments carried out at the Bio-CAT beamline were intended to examine a series of protein:protein and protein:DNA complexes that are involved in repairing damaged DNA. The one day of beamtime that was allocated through the entire cycle of the grant allowed us to carry out our initial characterization of these complexes; additional experiments are planned to follow up on our preliminary results, with allocation of beamtime being the limiting factor. Aside from our project on DNA repair, SAXS data was collected on a DNA endonuclease that is involved in pneumonia infections. These data resulted in a single publication describing our biochemical and biophysical analysis of this protein. The SAXS data collected at Bio-CAT allowed for determination of stoichiometry of this protein, which was previously debated, as other members of this family are known to dimerize. Additionally, ab-initio models were generated that allowed for comparison of the SAXS-based envelope model with homologous crystal structures.