RNA Virus Genomes


RNA (ribonucleic acid) viruses are the most abundant group of molecular parasites that infect humans, animals and plants. They are associated with important diseases such as human influenza, newly emerging haemorrhagic fevers or several forms of hepatitis. Virus particles are disparate in size, shape and composition, and enclose an RNA genome that can be either single‐stranded, double‐stranded, nonsegmented or segmented. The structural diversity of viral RNA is reflected in differences in their replication cycles that are completed through complex interactions between viral and host proteins. RNA viruses share error‐prone replication that confers on them the capacity to adapt to a wide range or environments. Despite considerable progress in the understanding of virus structure and expression of their genetic programmes, the success of preventive and control strategies has been limited. Application of Darwinian principles to RNA viruses might result in new approaches for viral disease control.

Keywords: RNA replication; virus life cycle; host function; viral protein synthesis; antiviral strategy; control of viral disease

Figure 1.

Some RNA viral genomes and their replication and expression strategies. A number of families of mammalian RNA viruses are included; additional features are given in Table . Continuous lines represent genomes of positive polarity and mRNAs. Discontinuous lines represent genomic RNAs of negative polarity and negative (antigenomic) strands of RNA viruses of positive polarities. Filled circles and squares at the 5′ end of genomic and mRNAs indicate a protein or a cap structure, respectively, linked to the RNA. As and Us refer to homopolymeric tracts found in genomic and antigenomic RNAs. A number of features such as relative size of genomic RNA and mRNAs, as well as the location and number of overlapping reading frames, may vary for individual representatives of the same virus family. Proteins are depicted as wavy lines with an indication of the N‐ and C‐termini. The location of a few coding regions is indicated on the genomes (S, structural proteins; NS nonstructural proteins; 3D, the picornavirus polymerase; PB1, subunit one of the influenza virus polymerase). In the case of Arenaviridae, the ambisense strategy is illustrated with one of the two genomic segments. Lines are not drawn to scale.

Figure 2.

Scheme of RNA genome replication and possible intermediates. Symbols are as in Figure . Arrows indicate the growing RNA chain. RI, replication intermediates (partially double‐stranded); RF, replicative form (double‐stranded).


Further Reading

Domingo E, Parrish CR and Holland JJ (eds) (2008) Origin and Evolution of Viruses, 2nd edn. Oxford: Elsevier.

Flint SJ, Enquist LW, Krug RM, Racaniello VR and Skalka AM (2009) Virology: Molecular Biology, Pathogenesis and Control, 3rd edn. Washington, DC: ASM Pressm.

Gesteland RF, Cech CR and Atkins JF (eds) (2006) The RNA World, 3rd edn. Cold Spring Harbor: Cold Spring Harbor Laboratory Press.

Knipe DM, Howley PM, Martin MA, Roizman B and Straus SE (eds) (2007) Fields Virology, 5th edn. Philadelphia: Wolters Kluwer, Lippincot Williams a & Wilkins.

Weissmann C (1974) The making of a phage. FEBS Letters 40: S10–S18.

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How to Cite close
Domingo, Esteban(Dec 2008) RNA Virus Genomes. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0001488.pub2]