Related Experiment Video
Updated: Aug 15, 2026

Rapid Screening of HIV Reverse Transcriptase and Integrase Inhibitors
Published on: April 9, 2014
HIV-2 genomic RNA contains a novel type of IRES located downstream of its initiation codon
Cécile H Herbreteau1, Laure Weill, Didier Décimo
1Inserm, U 412, Ecole Normale Supérieure de Lyon, LaboRétro, Unité de virologie humaine, IFR 128, 46 Allée d'Italie, 69364 Lyon 07, France.
Abstract:
Eukaryotic translation initiation begins with assembly of a 48S ribosomal complex at the 5' cap structure or at an internal ribosomal entry segment (IRES). In both cases, ribosomal positioning at the AUG codon requires a 5' untranslated region upstream from the initiation site. Here, we report that translation of the genomic RNA of human immunodeficiency virus type 2 takes place by attachment of the 48S ribosomal preinitiation complex to the coding region, with no need for an upstream 5' untranslated RNA sequence. This unusual mechanism is mediated by an RNA sequence that has features of an IRES with the unique ability to recruit ribosomes upstream from its core domain. A combination of translation assays and structural studies reveal that sequences located 50 nucleotides downstream of the AUG codon are crucial for IRES activity.
Related Concept Videos
RNA Interference
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
RNA Interference
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
LTR Retrotransposons
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
siRNA - Small Interfering RNAs
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
Viruses with RNA Genomes
Size and Structure of Viral Genomes

