Abstract
Double-strand DNA break repair and homologous recombination in Escherichia coil proceed by the RecBCD pathway, which is regulated by cis- acting elements known as χ sites. A crucial feature of this regulation is the RecBCD enzyme-directed loading of RecA protein specifically onto the 3'- terminal, χ-containing DNA strand. Here we show that RecBC enzyme (lacking the RecD subunit) loads RecA protein constitutively onto the 3'-terminal DNA strand, with no requirement for χ. This strand is preferentially utilized in homologous pairing reactions. We propose that RecA protein loading is a latent property of the RecBCD holoenzyme, which is normally blocked by the RecD subunit and is revealed following interaction with χ.
Original language | English (US) |
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Pages (from-to) | 901-911 |
Number of pages | 11 |
Journal | Genes and Development |
Volume | 13 |
Issue number | 7 |
State | Published - Apr 1 1999 |
Keywords
- χ
- DNA repair
- Helicase
- RecA
- RecBC
- Recombination
ASJC Scopus subject areas
- Genetics
- Developmental Biology