In vitro activities of purified visna virus integrase.

摘要: Abstract Although integration generally is considered a critical step in the retrovirus life cycle, it has been reported that visna virus, which causes degenerative neurologic disease sheep, can productively infect sheep choroid plexus cells without detectable integration. To ascertain whether integrase (IN) of virus an inherently defective enzyme and to create tools for further study phylogenetically related human immunodeficiency type 1 (HIV-1), we purified IN by using bacterial expression system applied various vitro oligonucleotide-based assays studying this protein. We found demonstrates full repertoire functions characteristic retroviral integrases. In particular, exhibits site-specific endonuclease activity following invariant CA two nucleotides from 3' ends viral DNA (processing activity), joins processed oligonucleotides sites on other (strand transfer or reverses reaction resolving complex mimics one end integrated into host (disintegration activity). addition, although HIV-1 cannot specifically nick ends, does process integrate ends.