Homologous recombination in real time: DNA strand exchange by RecA

T van der Heijden, M (Mauro) Modesti, S Hage, Roland Kanaar, C.L. Wyman, C (Cees) Dekker

Research output: Contribution to journalArticleAcademic

78 Citations (Scopus)

Abstract

Homologous recombination, the exchange of strands between different DNA molecules, is essential for proper maintenance and accurate duplication of the genome. Using magnetic tweezers, we monitor RecA-driven homologous recombination of individual DNA molecules in real time. We resolve several key aspects of DNA structure during and after strand exchange. Changes in DNA length and twist yield helical parameters for the protein-bound three-stranded structure in conditions in which ATP was not hydrolyzed. When strand exchange was completed under ATP hydrolysis conditions that allow protein dissociation, a "D wrap" structure formed. During homologous recombination, strand invasion at one end and RecA dissociation at the other end occurred at the same rate, and our single-molecule analysis indicated that a region of only about 80 bp is actively involved in the synapsis at any time during the entire reaction involving a long (similar to 1 kb) region of homology.
Original languageUndefined/Unknown
Pages (from-to)530-538
Number of pages9
JournalMolecular Cell
Volume30
Issue number4
DOIs
Publication statusPublished - 2008

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