Abstract
The polymerization of RecA on individual double-stranded DNA molecules is studied. A linear DNA (λ DNA, 48.5 Kb), anchored at one end to a cover glass and at the other end to an optically trapped 3-μm diameter polystyrene bead, serves as a template. The elongation caused by RecA assembly is measured in the presence of ATP and ATP[γS]. By using force extension and hydrodynamic recoil, a value of the persistence length of the RecA-DNA complex is obtained. In the presence of ATP, the polymer length is unstable, first growing to saturation and then decreasing. This suggests a transient dynamics of association and dissociation for RecA on a double-stranded DNA, the process being controlled by ATP hydrolysis. Part of this dynamics is suppressed in the presence of ATP[γS], leading to a stabilized RecA-DNA complex. A one-dimensional nucleation and growth model is presented that may account for the protein assembly.
| Original language | English |
|---|---|
| Pages (from-to) | 7916-7921 |
| Number of pages | 6 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 96 |
| Issue number | 14 |
| DOIs | |
| State | Published - 6 Jul 1999 |
| Externally published | Yes |
Keywords
- DNA-protein interactions
- Genetic recombination
- Nucleation and growth
- Optical tweezers
ASJC Scopus subject areas
- General