DNA is then synthesized completely down the template. DNA is synthesized to make the complementary strand to one end, at which point the strand again jumps to the other side of the template to complete the synthesis. The two jumps serve to bring the two halves of the LTR promoters, U3 and U5, together to form the functional unit. The double-stranded DNA thus formed then migrates to the nucleus to be integrated. Integration is a process in which DNA is inserted into the host genome where it can be stably transcribed for long periods of time under the control of its own promoters.
Integration is achieved when the integrase holds the DNA in a circle.
The ends of the circular DNA bind to the free ends of genomic DNA and the gaps are filled in afterwards by normal DNA repair mechanisms.