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. 1981 Aug 25;9(16):4201–4210. doi: 10.1093/nar/9.16.4201

Genetic recombination: recA protein promotes homologous pairing between duplex DNA molecules without strand unwinding.

E Cassuto, S C West, J Podell, P Howard-Flanders
PMCID: PMC1058476  PMID: 7029464

Abstract

The recA protein of Escherichia coli promotes pairing in vitro between covalent circular duplex DNA and homologous circular duplex DNA containing a single stranded region. We have used a filter binding assay to investigate the frequency of homologous pairing between gapped and intact duplex DNA when unwinding of the free 3' and 5' ends of the gapped molecules was blocked. In order to obtain DNA without free ends, the gapped DNA was treated with trimethylpsoralen and 360 nm light so as to introduce about 6 crosslinks per DNA molecule and the double stranded regions on either side of the gaps were then digested up to the first crosslinks with exonuclease III and lambda exonuclease. This treatment did not diminish the frequency of homologous pairing, an observation which is difficult to reconcile with models for recombination requiring strand unwinding before pairing.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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