RNase H activity associated with bacterially expressed reverse transcriptase of human T-cell lymphotropic virus III/lymphadenopathy-associated virus.
The reverse transcriptase polymerase of the human T-cell lymphotropic virus/lymphadenopathy-associated virus has been cloned into an expression vector and expressed in Escherichia coli. Two polypeptides of 66 and 51 kDa molecular mass are detectable in polymerase-expressing bacterial lysates with human patient sera. They are processed from a short-lived 120-kDa polyprotein precursor equivalent to a region consisting of polymerase, protease, and endonuclease. The 51 kDa protein appears to originate from the 66-kDa molecule; additional processing products are 32- and 15-kDa proteins. The bacterially expressed polymerase is enzymatically active and exhibits the template specificities, ion requirements, and response to inhibitors of the authentic enzyme. It was purified by DEAE-cellulose-, phosphocellulose-, and poly(rC)-agarose column chromatography followed by glycerol density gradient centrifugation. It copurifies with an RNase H activity, suggesting the existence of a virus-coded DNA polymerase-RNase H complex. The purified bacterial enzyme allows a safe large-scale screening for inhibitors of both activities.
D004722:Endoribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005798:Genes, Bacterial; D005822:Genetic Vectors; D006678:HIV / Q000201:enzymology*; D011401:Promoter Regions, Genetic; D011499:Protein Processing, Post-Translational; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism*; D012191:Retroviridae Proteins / Q000378:metabolism*; D016914:Ribonuclease H
D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D012191:Retroviridae Proteins; D012194:RNA-Directed DNA Polymerase; D004722:Endoribonucleases; D016914:Ribonuclease H