Title: Chi enhances heteroduplex DNA levels during recombination.
Authors: Holbeck, S L; Smith, G R
Published In Genetics, (1992 Dec)
Abstract: The major pathway of homologous recombination in Escherichia coli, the RecBCD pathway, is stimulated by Chi sites. To determine whether Chi enhances an early or late step in recombination, we measured formation of heteroduplex DNA (hDNA) in extracts of lambda-infected E. coli. Chi elevated hDNA levels in these extracts, supporting a role for Chi early (before hDNA formation) in recombination. RecA protein and RecBCD enzyme were both necessary for detection of hDNA, indicating that they, too, act early. Analysis of a panel of recBCD mutants indicated that Chi-nicking activity was needed for Chi's stimulation of hDNA formation. These results support a previously proposed model of recombination. Further results suggested that RecBCD enzyme has an additional role late in recombination.
PubMed ID: 1459441
MeSH Terms: Bacteriophage lambda/genetics; Base Sequence; DNA, Bacterial/genetics; DNA, Viral/genetics; Exodeoxyribonuclease V; Exodeoxyribonucleases/genetics*; Rec A Recombinases/genetics; Recombination, Genetic*