How strand exchange protein function benefits from ATP hydrolysis

[Display omitted] •The mechanism of homology search and strand exchange is driven by product stability not ATP hydrolysis.•ATP hydrolysis removes strand exchange proteins from the D-loop products they form.•ATP hydrolysis can enhance the efficiency of the homology search in biochemical systems.•ATP hydrolysis can act to disassemble and/or remodel pre-synaptic ssDNA filaments.•ATP hydrolysis corrects erroneous binding to double strand DNA in vivo. Members of the RecA family of strand exchange proteins carry out the central reaction in homologous recombination. These proteins are DNA-dependent ATPases, although their ATPase activity is not required for the key functions of homology search and strand exchange. We review the literature on the role of the intrinsic ATPase activity of strand exchange proteins. We also discuss the role of ATP-hydrolysis-dependent motor proteins that serve as strand exchange accessory factors, with an emphasis on the eukaryotic Rad54 family of double strand DNA-specific translocases. The energy from ATP allows recombination events to progress from the strand exchange stage to subsequent stages. ATP hydrolysis also functions to corrects DNA binding errors, including particularly detrimental binding to double strand DNA.