DNA RECOMBINATION. Base triplet stepping by the Rad51/RecA family of recombinases.
Science
; 349(6251): 977-81, 2015 Aug 28.
Article
in En
| MEDLINE
| ID: mdl-26315438
ABSTRACT
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.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Rec A Recombinases
/
DNA
/
Saccharomyces cerevisiae Proteins
/
Recombinases
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Rad51 Recombinase
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Homologous Recombination
Limits:
Humans
Language:
En
Journal:
Science
Year:
2015
Document type:
Article