Resumen
DNA strand exchange plays a central role in genetic recombination across all kingdoms of life, but the physical basis for these reactions remains poorly defined. Using single-molecule imaging, we found that bacterial RecA and eukaryotic Rad51 and Dmc1 all stabilize strand exchange intermediates in precise three-nucleotide steps. Each step coincides with an energetic signature (0.3 kBT) that is conserved from bacteria to humans. Triplet recognition is strictly dependent on correct Watson-Crick pairing. Rad51, RecA, and Dmc1 can all step over mismatches, but only Dmc1 can stabilize mismatched triplets. This finding provides insight into why eukaryotes have evolved a meiosis-specific recombinase. We propose that canonical Watson-Crick base triplets serve as the fundamental unit of pairing interactions during DNA recombination.
Idioma original | English (US) |
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Páginas (desde-hasta) | 977-981 |
Número de páginas | 5 |
Publicación | Science |
Volumen | 349 |
N.º | 6251 |
DOI | |
Estado | Published - ago 28 2015 |
Publicado de forma externa | Sí |
ASJC Scopus subject areas
- General