A dynamic model for replication protein A (RPA) function in DNA processing pathways
Processing of DNA in replication, repair and recombination pathways in cells of all organisms requires the participation of at least one major single stranded DNA (ssDNA) binding protein. This protein protects ssDNA from nucleolytic damage, prevents hairpin formation and blocks DNA reannealing until the processing pathway is successfully completed. Many ssDNA binding proteins interact physically and functionally with a variety of other DNA processing proteins. These interactions are thought to temporally order and guide the parade of proteins that 'trade places' on the ssDNA, a model known as 'hand off' as the processing pathway progresses. How this hand off mechanism works remains poorly understood. Recent studies of the conserved eukaryotic ssDNA binding protein replication protein A (RPA) suggest a novel mechanism by which proteins may trade places on ssDNA by binding to RPA and mediating conformation changes that alter the ssDNA binding properties of RPA. This article reviews the structure and function of RPA, summarizes recent studies of RPA in DNA replication and other DNA processing pathways, and proposes a general model for the role of RPA in protein mediated hand off.
Nucleic acids research