Abstract
In Escherichia coli, χ is a recombination hotspot that stimulates RecBCD- dependent exchange at and to one side of itself. χ active is highest at χ and decreases with distance from χ. The decrease in χ activity may be a simple property of the physical distance over which χ can stimulate recombination. Alternatively, the decay in χ activity with distance may reflect the high likelihood that χ-stimulated recombination occurs in a single χ-proximal act, to the exclusion of additional χ-stimulated exchanges more distal to χ. To test the models, we determined if χ activity decreases as a function of physical distance (i.e., DNA base pairs) or genetic distance (homologous DNA base pairs). Our results indicate that χ activity decays as a function of genetic distance. In addition, we found that the sbcB gene product (exonuclease 1, a 3' → 5' ssDNA exonuclease) modulates the distance over which χ can act. In contrast, the recJ gene product (a 5' → 3' ssDNA exonuclease) does not alter the decay of χ activity.
Original language | English (US) |
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Pages (from-to) | 805-812 |
Number of pages | 8 |
Journal | Genetics |
Volume | 141 |
Issue number | 3 |
State | Published - Jan 1 1995 |
Externally published | Yes |
ASJC Scopus subject areas
- Genetics