Human immunodeficiency virus integrase protein requires a subterminal position of its viral DNA recognition sequence for efficient cleavage.

摘要: textabstractRetroviral integration requires cis-acting sequences at the termini of linear double-stranded viral DNA and a product of retroviral pol gene, integrase protein (IN). IN is required sufficient for generation recessed 3' (the first step in proviral integration) species vitro. Human immunodeficiency virus type 1 (HIV-1) IN, expressed Escherichia coli, was purified to near homogeneity. The substrate sequence requirements specific cleavage were studied physical assay, using short duplex oligonucleotides that correspond HIV DNA. A few point mutations around site substantially reduced cleavage; most other did not have drastic effect, suggesting the sequence are limited. terminal 15 bp retroviral were demonstrated be recognition by IN. Efficient cutting cleavage site, phosphodiester bond side conserved CA-3' dinucleotide, located two nucleotides away from end viral DNA; however, low-efficiency observed when site one, three, four, or five terminus Increased detected CA-3' dinucleotide present as single-stranded found strong preference for promoting into rather than single-stranded