Recombinant HIV-1 nucleocapsid protein p15 produced as a fusion protein with glutathione S-transferase in Escherichia coli mediates dimerization and enhances reverse transcription of retroviral RNA.

Human immunodeficiency virus 1 (HIV-1) nucleocapsid protein p15 was produced as a fusion protein with glutathione S-transferase (GST) in Escherichia coli. Rapid purification of GST::p15 in an active form by one-step glutathione-agarose chromatography was accomplished in the presence of an antioxidant. Recombinant p15 fused to GST was shown to stimulate the dimerization of viral RNA. HIV-1 reverse transcriptase-catalyzed in vitro synthesis of minus-strand cDNA from synthetic human tRNA(Lys3UUU) and natural bovine tRNA(Lys3SUU) primer molecules was enhanced by GST::p15. GST produced in E.coli revealed no effect with respect to RNA dimerization and cDNA synthesis, demonstrating that both activities reside in the p15 portion of the fusion protein.