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NLM AIDSLINE

Structural and functional evidence that initiation and elongation of HIV-1 reverse transcription are distinct processes.




 

Biochimie. 1996;78(11-12):1087-96. Unique Identifier : AIDSLINE

Retroviral reverse transcription starts with the extension of a cellular tRNA primer bound near the 5' end of the viral genomic RNA at a site called the primer binding site (PBS). Formation of the HIV-1 initiation complex between tRNA3(Lys), viral RNA and reverse transcriptase probably occurs during encapsidation of these components. tRNA3(Lys) is thought to be selectively packaged by interaction with the reverse transcriptase domain of the Pr160Gag-Pol precursor protein, then annealed to the PBS of viral RNA with the help of the nucleocapsid protein. tRNA3(Lys) and HIV-1 viral RNA form a highly-structured complex, with extended interactions between the two molecules. Two different modes of reverse transcription have been distinguished: initiation, a tRNA3(Lys)-specific and distributive mode of polymerization corresponding to the addition of the first five nucleotides, followed by elongation, a non-specific and processive mode of DNA synthesis. These two modes are reminiscent of the initiation and elongation processes previously observed with DNA-dependent RNA polymerases.

*HIV-1/GENETICS *HIV-1/METABOLISM *HIV-1 Reverse Transcriptase/METABOLISM *Nucleic Acid Conformation *RNA, Transfer, Amino Acyl/BIOSYNTHESIS *RNA, Transfer, Amino Acyl/CHEMISTRY *Transcription, Genetic



 




Information in this article was accurate in September 30, 1997. The state of the art may have changed since the publication date. This material is designed to support, not replace, the relationship that exists between you and your doctor. Always discuss treatment options with a doctor who specializes in treating HIV.