Abstract
RecA is a DNA-dependent ATPase and mediates homologous recombination by first forming a filament on a single-stranded (ss) DNA. RecA binds preferentially to TGG repeat sequence, which resembles the recombination hot spot Chi (50-GCTG GTGG-30) and is the most frequent pattern (GTG) of the codon usage in Escherichia coli. Because of the highly dynamic nature of RecA filament formation, which consists of filament nucleation, growth and shrinkage, we need experimental approaches that can resolve each of these processes separately to gain detailed insights into the molecular mechanism of sequence preference. By using a single-molecule fluorescence assay, we examined the effect of sequence on individual stages of nucleation, monomer binding and dissociation. We found that RecA does not recognize the Chi sequence as a nucleation site. In contrast, we observed that it is the reduced monomer dissociation that mainly determines the high filament stability on TGG repeats. This sequence dependence of monomer dissociation is well-correlated with that of ATP hydrolysis, suggesting that DNA sequence dictates filament stability through modulation of ATP hydrolysis.
| Original language | English |
|---|---|
| Pages (from-to) | 7738-7744 |
| Number of pages | 7 |
| Journal | Nucleic Acids Research |
| Volume | 41 |
| Issue number | 16 |
| DOIs | |
| State | Published - Sep 2013 |
Bibliographical note
Funding Information:Korean Government Ministry of Education and Science Technology (MEST) [2011-0017435], Sogang University Research [SRF-20124003 to D.K.]; US National Science Foundation [PHY-0646550, PHY-0822613 to T.H.]; US National Institutes of Health [GM065367 to T.H.]; European Research Council under the European Union’s Seventh Framework Programme [FP7/2007-2013] / ERC grant agreement n° [309509] (to C.J.). Funding for open access charge: Korean Government (MEST) [2011-0017435].