Double-stranded gap repair of DNA by gene conversion in Escherichia coli.
We demonstrated repair of a double-stranded DNA gap through gene conversion by a homologous DNA sequence in Escherichia coli. We made a double-stranded gap in one of the two regions of homology in an inverted orientation on a plasmid DNA molecule and introduced it into an E. coli strain which has the RecE system of recombination (genotype; sbcA23 recB21 recC22). We detected repair products by genetic selection. The repair products were those expected by the double-strand-gap repair model. Gene conversion was frequently accompanied by crossing over of the flanking sequences as in eukaryotes. This double-strand gap repair mechanism can explain plasmid recombination in the absence of an artificial double-stranded break reported in a companion study by Yamamoto et al.
D003434:Crossing Over, Genetic; D004260:DNA Repair; D004269:DNA, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D005785:Gene Conversion; D010957:Plasmids; D011995:Recombination, Genetic
D004269:DNA, Bacterial