Molecular Basis of Double-Strand DNA Break Repair: The Critical Structure of the RAD52/RPA Complex

摘要

Understanding DNA metabolism such as DNA repair and recombination- based repair is of central importance if we are to tackle the task of finding treatments and cures for breast cancer. RAD52 has specific interactions with RAD51, RPA and DNA (1,2,3). The binding of RAD52 to ends of double-strand breaks has been found to be a key initiation step to DNA repair by homologous recombination. RAD52 also has a self-association domain and it has been shown by EM to self-associate in solution to form ring structures (4,5). RPA is involved in many DNA metabolic processes including replication, repair, transcription and recombination. It consist of a 14, 32 and a 70 subunit which associates together to form a heterotrimer (6,7). The purpose of this research is to understand how RAD52 and RPA interact with each other at the molecular level. The crystallization of the RPA l4/32-RAD52 (221-418) complex and a three dimensional structural view of these two proteins will elucidate how these proteins are interacting. A three-dimensional structure of the RPA/RAD52 complex will reveal in depth structural knowledge of protein-protein contact surfaces, side chain interactions and binding sites for other interacting proteins. This will serve as a model for other proteins interacting with RPA 32 (such as XPA, uracil DNA glycosylase) and RAD52 (221-418) (such as RAD51). A model of the protein interactions will greatly contribute to our basic understanding of DNA repair by homologous recombination and will lead closer to future prevention, therapy and treatment of breast cancer.