1. The RNA : DNA duplex then exits through another basic depression. 2. They can also form triple helices in conjunction with the DNA duplex . 3. Each daughter strand becomes part of a new DNA duplex . 4. A-DNA, is a form of the DNA duplex observed under dehydrating conditions. 5. Step 2 : RecBCD initiates unwinding of the DNA duplex through ATP-dependent helicase activity. 6. New DNA synthesis fills in any gaps, and ligation restores the DNA duplex as two continuous strands. 7. Topoisomerase IV in " E . coli " unlinks or decatenates the two circular DNA duplexes . 8. This tail can be bound by RecA protein, which promotes strand exchange with an intact homologous DNA duplex . 9. Helicase is an enzyme which breaks hydrogen bonds between the base pairs in the middle of the DNA duplex . 10. Step 6 : RecBCD unbinds from the DNA duplex , leaving a RecA nucleoprotein filament on the 3'tail.
