Topological analysis of the role of homology in Flp-mediated recombination.
Recombination by the Flp recombinase of Saccharomyces cerevisiae is known to be inhibited by heterology of the overlap regions of the two recombining DNA targets (FRT sites). We have used topological analysis to show that Flp can promote two rounds of intramolecular recombination between heterologous FRT sites contained within the same supercoiled plasmid. The products are in parental nonrecombinant configuration. Thus, heterology may appear to "block" recombination by rendering the heteroduplex recombinant products unstable, thus favoring a second round of recombination to homoduplex (but parental) products. Hence, homology in the core region is not a requirement for the recombination reaction by Flp but for the formation of recombinant products.
Azam
N
N
Department of Medical Genetics and Microbiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
Dixon
J E
JE
Sadowski
P D
PD
D001483:Base Sequence; D001665:Binding Sites; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D004278:DNA, Superhelical / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000201:enzymology
D004278:DNA, Superhelical; D005656:Fungal Proteins; D004254:DNA Nucleotidyltransferases; C045119:FLP recombinase