It is a key component in the pre-integration complex (PIC).
Both the Central catalytic domain and C-terminal domains have been shown to bind both viral and cellular DNA. Currently no crystal structure data exists with Integrase bound to its DNA substrates.
Additionally, several host cellular proteins have been shown to interact with integrase and may facilitate the integration process.
Integrase acts to insert the proviral DNA into the host chromosomal DNA, a step which is essential for HIV replication.
Integrase catalyzes two reactions;
Integration of the proviral DNA is essential for the subsequent transcription of the viral genome which leads to production of new viral genomic RNA and viral proteins needed for the production of the next round of infectious virus.
Essentially, integrase is a key step in allowing viral DNA to become a permanent member of the host genome. This integrated proviral DNA is then translated using host cell machinery (see translation) into viral proteins.
In November 2005, data from a phase 2 study of an investigational HIV integrase inhibitor, MK-0518, demonstrated that the compound had potent antiviral activity. On October 12, 2007, the Food and Drug Administration (U.S.) approved the integrase inhibitor Raltegravir (MK-0518, brand name IsentressTM). As of April 2008, this is the only integrase inhibitor approved for treating HIV Infection.