Can recA protein promote homologous pairing between duplex regions of DNA?

AUTOR(ES)

Cassuto, E

RESUMO

RecA protein has been shown to promote the formation of joint molecules between intact duplex DNA and homologous gapped DNA. When examined by electron microscopy, such joint molecules display a junction that is, in most cases, distant from the site of the gap. This led us to test whether the observed location of the joint was due to pairing at the gap followed by branch migration, or whether recA-promoted pairing could also take place between duplex homologous regions away from the gap. To test the latter possibility, intact duplex DNA was incubated with DNA which contained a gap in a region of non-homology. Joint molecules were detected by filter binding assay and by electron microscopy at about one-third of the yield observed for fully homologous molecules. These results indicate that initial homologous pairing promoted by recA protein is not restricted to the single-stranded region in the gap but can also take place in regions where both molecules are duplex.

Documentos Relacionados

• recA protein promotes homologous-pairing and strand-exchange reactions between duplex DNA molecules.
• Initiation of genetic recombination: homologous pairing between duplex DNA molecules promoted by recA protein.
• Genetic recombination: recA protein promotes homologous pairing between duplex DNA molecules without strand unwinding.
• Nucleosomes on linear duplex DNA allow homologous pairing but prevent strand exchange promoted by RecA protein.
• Homologous pairing in genetic recombination: complexes of recA protein and DNA.