Fig. 7
From: A structural and dynamic model for the assembly of Replication Protein A on single-stranded DNA
Proposed model of DBD dynamics when multiple RPAs are associated with ssDNA. a Schematic of yeast RPA (ScRPA) illustrating the DNA-binding domains (DBDs) F, A, B, C, D. Subunits of the RPA heterotrimer (Rfa1, Rfa2, and Rfa3) are colored as in Fig. 2. The winged-helix domain (WH) and phosphorylation motif (P-motif) of Rfa2 are also shown for completeness. b Unmodified RPA binds to ssDNA tracts with varying conformational states. DBD-A and DBD-B are dynamic, whereas the Tri-C is more stable. Through diffusion on ssDNA RPAs can interact with each other via an interaction between DBD-A and DBD-E. This interaction allows RPA to pass ssDNA from one molecule to another. c An S178D phosphomimetic mutant RPA has an enhanced DBD-A–DBD-E interaction that results in cooperative assembly of RPA on ssDNA. The positioning of DBD-A may not be associated with ssDNA and this allows easier access of the nucleic acid to other processing factors such as Rad51
