Fig. 8: A schematic concept of a biophysical mechanism involving multiple RPA binding dynamics on long ssDNA.
From: ssDNA accessibility of Rad51 is regulated by orchestrating multiple RPA dynamics
RPA ssDNA binding mode transition regulates RPA spacing on ssDNA, where RPA shifting from FLBM (30-nt mode) to PBMs (e.g. 20-nt mode) tightens the spacing between RPA molecules on ssDNA-RPA complex. Cell may evoke more PBMs of RPA binding to ensure low ssDNA accessibility as the protection mode in which RPA molecules tightly align on ssDNA to offer protection for the fragile ssDNA intermediates in replication forks, while that cell may inhibit RPA shifting to PBMs to provide high ssDNA accessibility as the action mode in which RPA binding leaves more uncovered ssDNA gaps to make room for loading of ssDNA processing proteins like the Rad51 recombinase during HR repair.
