RecA-mediated joint molecule formation between O-methylated RNA/DNA hairpins and single-stranded targets.
Chimeric oligonucleotides consisting of one DNA strand paired with an O-methylated RNA strand interrupted by six DNA residues have been used in gene targeting experiments. Here we demonstrate that these hairpins can form a heteroduplex (or joint molecule) with single-stranded DNA targets in a reaction mediated by the E. coli RecA protein. One end of the double hairpin may unwind to form a 14-base-RecA filament which initiates the reaction. Chimeric oligonucleotides containing only O-methylated RNA residues on one strand or truncated hairpins lacking this 14-base segment did not participate in RecA-driven heteroduplex formation under these reaction conditions. The results presented here represent a first step in studying one facet of a strategy which uses O-methylated RNA residues as participants in homologous pairing events.
Havre
P A
PA
Department of Microbiology/Immunology, Kimmel Cancer Institute, Thomas Jefferson University, Philadelphia, PA 19107, USA.
Kmiec
E B
EB
D001483:Base Sequence; D004277:DNA, Single-Stranded / Q000737:chemistry*; D008745:Methylation; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry; D011485:Protein Binding; D012313:RNA / Q000737:chemistry*; D011938:Rec A Recombinases / Q000737:chemistry*
D004277:DNA, Single-Stranded; D009841:Oligonucleotides; D012313:RNA; D011938:Rec A Recombinases