Viral integrase
Enzyme produced by a virus that enables the integration of viral DNA into the host chromosomal DNA. For retroviruses integration, staggered cleavage of the target DNA results in duplication of host target DNA at both ends of the provirus genome while two nucleotides at each end of the long terminal repeats are lost. Integration of the proviral DNA results in permanent insertion of the viral genome into the host chomosomal DNA. Proviral DNA can remain latent and be passively replicated along with the host genome and passed on to the original cell's offspring or transcription may occur and leads to production of new viral components needed for the production of the next round of infectious virus.