Two distinct conformational states define the interaction of human RAD51-ATP with single-stranded DNA.


Type
Article
Change log
Authors
Brouwer, Ineke 
Moschetti, Tommaso 
Candelli, Andrea 
Garcin, Edwige B 
Modesti, Mauro 
Abstract

An essential mechanism for repairing DNA double-strand breaks is homologous recombination (HR). One of its core catalysts is human RAD51 (hRAD51), which assembles as a helical nucleoprotein filament on single-stranded DNA, promoting DNA-strand exchange. Here, we study the interaction of hRAD51 with single-stranded DNA using a single-molecule approach. We show that ATP-bound hRAD51 filaments can exist in two different states with different contour lengths and with a free-energy difference of ~4 kBT per hRAD51 monomer. Upon ATP hydrolysis, the filaments convert into a disassembly-competent ADP-bound configuration. In agreement with the single-molecule analysis, we demonstrate the presence of two distinct protomer interfaces in the crystal structure of a hRAD51-ATP filament, providing a structural basis for the two conformational states of the filament. Together, our findings provide evidence that hRAD51-ATP filaments can exist in two interconvertible conformational states, which might be functionally relevant for DNA homology recognition and strand exchange.

Description
Keywords
DNA repair, RAD51, homologous recombination, single‐stranded DNA, Adenosine Triphosphate, Crystallography, X-Ray, DNA, DNA Breaks, Double-Stranded, DNA Repair, DNA Replication, DNA, Single-Stranded, DNA-Binding Proteins, Homologous Recombination, Models, Molecular, Molecular Conformation, Nucleoproteins, Rad51 Recombinase
Journal Title
EMBO J
Conference Name
Journal ISSN
0261-4189
1460-2075
Volume Title
37
Publisher
EMBO
Sponsorship
Wellcome Trust (104641/Z/14/Z)