Roles of Gag and NCp7 in Facilitating \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathbf{tRNA}_{3}^{\mathbf{Lys}}\) \end{document} Annealing to Viral RNA in Human Immunodeficiency Virus Type 1
Authors: Guo Fei , Saadatmand Jenan , Niu Meijuan , Kleiman Lawrence 
Published: June 2009

ABSTRACT

In protease-negative human immunodeficiency virus type 1 (HIV-1) [Pr(-)], the amount of

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annealed by Gag is modestly reduced (∼25%) compared to that annealed by mature nucleocapsid (NCp7) in protease-positive HIV-1 [Pr(+)]. However, the

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annealed by Gag also has a strongly reduced ability to initiate reverse transcription and binds less tightly to viral RNA. Both in vivo and in vitro, APOBEC3G (A3G) inhibits

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annealing facilitated by NCp7 but not annealing facilitated by Gag. While transient exposure of Pr(-) viral RNA to NCp7 in vitro returns the quality and quantity of

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annealing to Pr(+) levels, the presence of A3G both prevents this rescue and creates a further reduction in

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annealing. Since A3G inhibition of NCp7-facilitated

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annealing in vitro requires the presence of A3G during the annealing process, these results suggest that in Pr(+) viruses NCp7 can displace Gag-annealed

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and re-anneal it to viral RNA, the re-annealing step being subject to A3G inhibition. This supports the possibility that the initial annealing of

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in wild-type, Pr(+) virus may be by Gag and not by NCp7, perhaps offering the advantage of Gag's preference for binding to RNA stem-loops in the 5′ region of viral RNA near the

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annealing region.