title: Double-stranded strong-stop DNA and the second template switch in human immunodeficiency virus (HIV) DNA synthesis.
abstract: Synthesis of unintegrated retroviral DNA via reverse transcription is thought to involve two separate template switches. Minus-strand strong-stop DNA, a major product of in vitro reactions using detergent-treated virions, is synthesized prior to the first template switch. Plus-strand strong-stop DNA, which is found base-paired to near full-length minus-strand DNA in infected cells, is believed to be synthesized before the second template switch. Using a synchronized, one-step HIV infection model, we report here the detection in acutely infected cells of a novel double-stranded strong-stop HIV DNA with a discrete length of approximately 650 base pairs, commencing at or near the left hand end of the right-hand U3 region of the HIV long terminal repeat. The plus-strand of this double-stranded strong-stop DNA possesses the primer binding site sequence and appears to be synthesized prior to the completion of the synthesis of its complementary minus-strand. In contrast, the minus-strand of the double-stranded strong-stop DNA lacks the primer binding site sequence after RNaseH digestion. We propose that a transient free plus-strand strong-stop DNA is released from its template by displacement synthesis and subsequently used as template for the synthesis of its complementary minus-strand. The proposed transient free plus-strand strong-stop DNA may also mediate the second template switch.
authors: National Centre for HIV Virology Research, Institute of Medical and Veterinary Science, Adelaide, South Australia.
authors: P
authors: P
authors: Li
authors: A J
authors: AJ
authors: Stephenson
authors: L J
authors: LJ
authors: Kuiper
authors: C J
authors: CJ
authors: Burrell
mesh_terms: D001483:Base Sequence; D015139:Blotting, Southern; D002478:Cells, Cultured; D004279:DNA, Viral / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D006678:HIV / Q000235:genetics* / Q000254:growth & development; D008957:Models, Genetic; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D012045:Regulatory Sequences, Nucleic Acid; D014158:Transcription, Genetic
chemical_list: D004279:DNA, Viral; D015345:Oligonucleotide Probes