Formation of base triplets by non-Watson-Crick bonds mediates homologous recognition in RecA recombination filaments.
Whereas complementary strands of DNA recognize one another by forming Watson-Crick base pairs, the way in which RecA protein enables a single strand to recognize homology in duplex DNA has remained unknown. Recent experiments, however, have shown that a single plus strand in the RecA filament can recognize an identical plus strand via bonds that, by definition, are non-Watson-Crick. In experiments reported here, base substitutions had the same qualitative and quantitative effects on the pairing of two identical strands in the RecA filament as on the recognition of duplex DNA by a third strand, indicating that similar non-Watson-Crick interactions govern both reactions.
Department of Genetics, Yale University School of Medicine, New Haven, CT 06510.
B J
BJ
Rao
C M
CM
Radding
D001482:Base Composition; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D006860:Hydrogen Bonding; D008957:Models, Genetic; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis / Q000737:chemistry; D011938:Rec A Recombinases / Q000378:metabolism*
D009838:Oligodeoxyribonucleotides; D004247:DNA; D011938:Rec A Recombinases