{"id":177689,"date":"2023-12-07T21:26:39","date_gmt":"2023-12-08T03:26:39","guid":{"rendered":"https:\/\/lifeboat.com\/blog\/2023\/12\/the-virus-zoo-a-primer-on-molecular-virology"},"modified":"2023-12-07T21:26:39","modified_gmt":"2023-12-08T03:26:39","slug":"the-virus-zoo-a-primer-on-molecular-virology","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2023\/12\/the-virus-zoo-a-primer-on-molecular-virology","title":{"rendered":"The Virus Zoo: A Primer on Molecular Virology"},"content":{"rendered":"<p><a class=\"aligncenter blog-photo\" href=\"https:\/\/lifeboat.com\/blog.images\/the-virus-zoo-a-primer-on-molecular-virology2.jpg\"><\/a><\/p>\n<p><em>Genome and Structure:<\/em><\/p>\n<p>HIV\u2019s genome is a 9.7 kb linear positive-sense ssRNA.<sup>1<\/sup> There is a m<sup>7<\/sup>G-cap (specifically the standard eukaryotic m<sup>7<\/sup>GpppG as added by the host\u2019s enzymes) at the 5\u2019 end of the genome and a poly-A tail at the 3\u2019 end of the genome.<sup>2<\/sup> The genome also has a 5\u2019-LTR and 3\u2019-LTR (long terminal repeats) that aid its integration into the host genome after reverse transcription, that facilitate HIV genetic regulation, and that play a variety of other important functional roles. In particular, it should be noted that the integrated 5\u2019UTR contains the HIV promoter called U3.<sup>3,4<\/sup><\/p>\n<p>HIV\u2019s genome translates three polyproteins (as well as several accessory proteins). The Gag polyprotein contains the HIV structural proteins. The Gag-Pol polyprotein contains (within its Pol component) the enzymes viral protease, reverse transcriptase, and integrase. The Gag-Pol polyprotein is produced via a &minus;1 ribosomal frameshift at the end of Gag translation. Because of the lower efficiency of this frameshift, Gag-Pol is synthesized 20-fold less frequently than Gag.<sup>5<\/sup> The frameshift\u2019s mechanism depends upon a slippery heptanucleotide sequence UUUUUUA and a downstream RNA secondary structure called the frameshift stimulatory signal (FSS).<sup>6<\/sup> This FSS controls the efficiency of the frameshift process.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Genome and Structure: HIV\u2019s genome is a 9.7 kb linear positive-sense ssRNA.1 There is a m7G-cap (specifically the standard eukaryotic m7GpppG as added by the host\u2019s enzymes) at the 5\u2019 end of the genome and a poly-A tail at the 3\u2019 end of the genome.2 The genome also has a 5\u2019-LTR and 3\u2019-LTR (long terminal [\u2026]<\/p>\n","protected":false},"author":662,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11,412],"tags":[],"class_list":["post-177689","post","type-post","status-publish","format-standard","hentry","category-biotech-medical","category-genetics"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/177689","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/662"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=177689"}],"version-history":[{"count":0,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/177689\/revisions"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=177689"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=177689"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=177689"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}