Efficient support of virus-like particle assembly by the HIV-1 packaging signal.
Efficient support of virus-like particle assembly by the HIV-1 packaging signal.
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作者：
Comas-Garcia M;Kroupa T;Datta SA;Harvin DP;Hu WS;Rein A
逆转录病毒颗粒的主要结构组分是Gag蛋白。逆转录病毒基因组RNA含有“包装信号”（“包装”），并以非常高的选择性包装在病毒颗粒中。然而，如果没有基因组RNA存在，Gag组装成含有细胞mRNA分子的颗粒。基因组RNA在病毒组装过程中通常被选择的机制尚不清楚。我们以前报道过，在生理离子强度，重组HIV-1 Gag与有或没有RNA结合具有相似的亲和力，并提出基因组RNA被选择性包装，因为与RNA结合比其他RNA更有效地启动颗粒组装。我们现在提供的数据直接支持这一假设。我们还表明，一个或多个短的未配对的G残基的延伸是重要的元素，cDNAs可能不局限于一个单一的结构元素，但可能分布在>100个碱基。
The principal structural component of a retrovirus particle is the Gag protein. Retroviral genomic RNAs contain a ‘packaging signal’ (‘Ψ') and are packaged in virus particles with very high selectivity. However, if no genomic RNA is present, Gag assembles into particles containing cellular mRNA molecules. The mechanism by which genomic RNA is normally selected during virus assembly is not understood. We previously reported that at physiological ionic strength, recombinant HIV-1 Gag binds with similar affinities to RNAs with or without Ψ, and proposed that genomic RNA is selectively packaged because binding to Ψ initiates particle assembly more efficiently than other RNAs. We now present data directly supporting this hypothesis. We also show that one or more short stretches of unpaired G residues are important elements of Ψ; Ψ may not be localized to a single structural element, but is probably distributed over >100 bases.