The name picornavirus is derived from pico for small and ribonucleic acid (RNA), denoting the chemical nature of the genome. Virions are nonenveloped icosahedral particles approximately 30 nm in diameter. The capsid is constructed from 60 copies of each of four structural proteins, which account for 70% of the particle mass and enclose the single‐strand genome of 7500–8500 nucleotides. The positive‐strand genome acts directly as a messenger RNA to template a single polyprotein product. This is subsequently processed by virally encoded proteases into mature active proteins. Several intermediate products have distinct functions to the final fully processed proteins. Replication of the genome is initiated by an uridylated peptide and proceeds via a negative‐strand intermediate template. Picornaviruses are among the smallest pathogens of vertebrates and are responsible for many important diseases in humans and animals.

Key Concepts

  • There are effective vaccines against polio, hepatitis A and foot‐and‐mouth disease viruses. In addition, movement control and slaughter is used to control foot‐and‐mouth disease. There are no licensed drugs for picornavirus infections.
  • Genome sequence comparisons have replaced biological and biophysical comparisons as the bases for classification within the family.
  • Picornavirus particles comprise 60 copies each of four structural proteins, which form a quasi‐T1 icosohedral capsid encasing the single‐strand RNA genome.
  • The picornavirus RNA genome functions as a messenger RNA to template the synthesis of a single polyprotein, which is posttranslationally processed by viral proteases.
  • Picornaviruses bind to cell‐specific surface receptors, and this interaction is an important factor in determining host and tissue specificity of each virus.
  • Picornaviruses cannot gain entry to cells by membrane fusion, as is the case for enveloped viruses, and require special mechanisms to breach cellular membranes and safely deliver the genome into the host cell.
  • Genome replication occurs in association with virus‐modified cellular membranes. Viral RNA templates complementary negative‐strand molecules, which in turn template multiple positive‐strand copies. The synthesis of all RNA molecules is initiated by an uridylated peptide primer.
  • The mechanisms of transmission of infection play key roles in the epidemiology of picornavirus infections.
  • Picornaviruses are responsible for a wide range of clinical diseases resulting from multiple factors such as receptor specificity, tissue‐specific susceptibility, virulence and the mechanisms of transmission.

Keywords: positive‐strand RNA; nonenveloped viruses; infectious disease; virus structure; virus replication

Figure 1. Evolutionary relationships of 50 taxa. Evolutionary history was inferred using the Neighbour‐Joining method. The optimal tree with the sum of branch length = 23.63528644 is shown. The tree is drawn to scale, with branch lengths in the same units as those of the evolutionary distances used to infer the phylogenetic tree. The evolutionary distances were computed using the JTT matrix‐based method and are in the units of the number of amino acid substitutions per site. The analysis involved 50 amino acid sequences. All ambiguous positions were removed for each sequence pair. There were a total of 528 positions in the final dataset. Evolutionary analyses were conducted in MEGA6. Source: Courtesy of Nick Knowles.
Figure 2. Picornavirus particle structure. (a) Basic ‘jelly roll’ fold and structures of poliovirus proteins VP1, 2 and 3. (b) The protomeric subunit of the icosahedral capsid showing its orientation with respect to the 5,3,2 symmetry axes. The proteins are colour coded as in (a), with VP4 (a short internal protein) coloured green. (c) Surface representation of the poliovirus capsid (rotated 90° with respect to (b)). The capsid is coloured by radial depth (green innermost through light‐blue to navy outermost) to highlight the most exposed capsid features. A particle twofold axis is shown by a red ellipsoid. (d) Surface representation of the poliovirus receptor (shown in purple/grey) bound to poliovirus (depicted as in (c)). (e) Close‐up of the electron density map (blue) for a twofold region of EV71 (an enterovirus closely related to poliovirus). The proteins are depicted by C‐alpha trace with VP2 in green and VP3 in red. The twofold axis, marked by a red ellipsoid, is straddled by helices from VP2. (f) Close‐up of a twofold of an expanded empty EV71 particle. Conformational changes have led to separation of the twofold helices to open up holes at the twofold and adjacent to the twofold. These holes facilitate the egress of VP4 and the N‐terminus of VP1 from the particle interior. Both are candidates for membrane association and channel formation to transfer of viral genome (which may also exit here) to the cell cytoplasm. (g) Close‐up of an electron density map (blue) showing a twofold axis of an uncoating intermediate of the enterovirus CAV16 (C‐alpha traces are used to depict VP2 (green), VP3 (red)). The N‐terminus of VP1 (drawn in magenta and labelled VP1) has been captured traversing from the particle interior to exit through the hole adjacent to the twofold (as shown in (f)). Source: (a)–(d) Courtesy of Jim Hogle and Mike Strauss. (e)–(g). Courtesy of Liz Fry and Jingshan Ren.
Figure 3. Genome structure and polyprotein processing of viruses of representative genera of the Picornaviridae.
Figure 4. Receptor proteins used by different picornaviruses. CAR, Coxsackie/adenovirus receptor; PVR, poliovirus receptor; ICAM‐1, intercellular adhesion molecule 1; VCAM‐1, vitronectin cellular adhesion molecule 1; DAF, decay‐accelerating factor; HAVcr‐1, hepatitis A virus receptor 1; LDLR, low‐density lipid receptor; α2β1, integrin; αvβ3, integrin; SCARB2, scavenger receptor class B2; CBV, Coxsackie B virus; PV, poliovirus; HRV, human rhinovirus; EMCV, encephalomyocarditis virus; HAV, hepatitis A virus; EV1, echovirus 1; FMDV, foot‐and‐mouth disease virus and CAV9, Coxsackie virus 9. Source: Courtesy of Dr D Evans and Liz Fry.


Acharya R, Fry E, Stuart D, et al. (1989) The three‐dimensional structure of foot‐and‐mouth disease virus at 2.9 A resolution. Nature 337: 709–716.

Adams P, Kandiah E, Effantin G, Steven AC and Ehrenfeld E (2009) Poliovirus 2C protein forms homo‐oligomeric structures required for ATPase activity. Journal of Biological Chemistry 284: 22012–22021.

Belsham GJ and Bostock CJ (1988) Studies on the infectivity of foot‐and‐mouth disease virus RNA using microinjection. Journal of General Virology 69 (part 2): 265–274.

Belsham GJ (2009) Divergent picornavirus IRES elements. Virus Research 139: 183–192.

Bostina M, Levy H, Filman DJ and Hogle JM (2011) Poliovirus RNA is released from the capsid near a twofold symmetry axis. Journal of Virology 85: 776–783. DOI: 10.1128/JVI.00531-10.

Brandenburg B, Lee LY, Lakadamyali M, et al. (2007) Imaging poliovirus entry in live cells. PLoS Biology 5: e183.

Cello J, Paul AV and Wimmer E (2002) Chemical synthesis of poliovirus cDNA: generation of infectious virus in the absence of natural template. Science 297: 1016–1018.

Cho MW, Richards OC, Dmitrieva TM, Agol V and Ehrenfeld E (1993) RNA duplex unwinding activity of poliovirus RNA‐dependent RNA polymerase 3Dpol. Journal of Virology 67: 3010–3018.

Coyne CB, Shen L, Turner JR and Bergelson JM (2007) Coxsackievirus entry across epithelial tight junctions requires occludin and the small GTPases Rab34 and Rab5. Cell Host & Microbe 2: 181–192.

Curry S, Fry E, Blakemore W, et al. (1997) Dissecting the roles of VP0 cleavage and RNA packaging in picornavirus capsid stabilization: the structure of empty capsids of foot‐and‐mouth disease virus. Journal of Virology 71: 9743–9752.

Devaney MA, Vakharia VN, Lloyd RE, Ehrenfeld E and Grubman MJ (1988) Leader protein of foot‐and‐mouth disease virus is required for cleavage of the p220 component of the cap‐binding protein complex. Journal of Virology 62: 4407–4409.

Domingo E, Escarmis C, Martinez MA, Martinez‐Salas E and Mateu MG (1992) Foot‐and‐mouth disease virus populations are quasispecies. Current Topics in Microbiology and Immunology 176: 33–47.

Donnelly ML, Luke G, Mehrotra A, et al. (2001) Analysis of the aphthovirus 2A/2B polyprotein ‘cleavage’ mechanism indicates not a proteolytic reaction, but a novel translational effect: a putative ribosomal ‘skip’. Journal of General Virology 82: 1013–1025.

Dvorak CM, Hall DJ, Hill M, et al. (2001) Leader protein of encephalomyocarditis virus binds zinc, is phosphorylated during viral infection, and affects the efficiency of genome translation. Virology 290: 261–271.

Feng Z, Hensley L, McKnight KL, Hu F, Madden V, Ping L, Jeong SH, Walker C, Lanford RE, Lemon SM. (2013) A pathogenic picornavirus acquires an envelope by hijacking cellular membranes. Nature 496 (7445): 367–371. doi: 10.1038/nature12029. PMID:23542590

Ferrer‐Orta C, Arias A, Pérez‐Luque R, Escarmís C, Domingo E, Verdaguer N. (2007) Sequential structures provide insights into the fidelity of RNA replication. Proceedings of the National Academy of Sciences of the United States of America; 104 (22): 9463–9468. PMID:17517631

Ghadge GD, Ma L, Sato S, Kim J and Roos RP (1998) A protein critical for a Theiler's virus‐induced immune system‐mediated demyelinating disease has a cell type‐specific antiapoptotic effect and a key role in virus persistence. Journal of Virology 72: 8605–8612.

Groppo R and Palmenberg AC (2007) Cardiovirus 2A protein associates with 40S but not 80S ribosome subunits during infection. Journal of Virology 81: 13067–13074.

Guarne A, Tormo J, Kirchweger R, et al. (1998) Structure of the foot‐and‐mouth disease virus leader protease: a papain‐like fold adapted for self‐processing and eIF4G recognition. EMBO Journal 17: 7469–7479.

Hales LM, Knowles NJ, Reddy PS, et al. (2008) Complete genome sequence analysis of Seneca Valley virus‐001, a novel oncolytic picornavirus. Journal of General Virology 89: 1265–1275.

Hewat EA, Neumann E, Conway JF, et al. (2000) The cellular receptor to human rhinovirus 2 binds around the 5‐fold axis and not in the canyon: a structural view. EMBO Journal 19: 6317–6325.

Hindiyeh M, Li QH, Basavappa R, Hogle JM and Chow M (1999) Poliovirus mutants at histidine 195 of VP2 do not cleave VP0 into VP2 and VP4. Journal of Virology 73: 9072–9079.

Hogle JM, Chow M and Filman DJ (1985) Three‐dimensional structure of poliovirus at 2.9 A resolution. Science 229: 1358–1365.

Huang JA, Ficorilli N, Hartley CA, et al. (2001) Equine rhinitis B virus: a new serotype. Journal of General Virology 82: 2641–2645.

Harutyunyan S, Kumar M, Sedivy A, Subirats X, Kowalski H, Köhler G, Blaas D. (2013) Viral uncoating is directional: exit of the genomic RNA in a common cold virus starts with the poly‐(A) tail at the 3′‐end. PLoS Pathogens 9 (4): e1003270. doi:10.1371/journal.ppat.1003270. PMID:23592991

Jacobs SE, Lamson DM, St George K and Walsh TJ (2013) Human rhinoviruses. Clinical Microbiology Reviews 26 (1): 135–162. DOI: 10.1128/CMR.00077-12.

Kong WP, Roos RP.(1991) Alternative translation initiation site in the DA strain of Theiler's murine encephalomyelitis virus. Journal of Virology 65 (6): 3395–3399. PMID:2033677

Lindberg AM and Johansson S (2002) Phylogenetic analysis of Ljungan virus and A‐2 plaque virus, new members of the Picornaviridae. Virus Research 85: 61–70.

Logan D, Abu‐Ghazaleh R, Blakemore W, et al. (1993) Structure of a major immunogenic site on foot‐and‐mouth disease virus. Nature 362: 566–568.

Luo M, Vriend G, Kamer G and Rossmann MG (1989) Structure determination of Mengo virus. Acta Crystallographica. Section B 45 (part 1): 85–92.

McKnight KL and Lemon SM (1998) The rhinovirus type 14 genome contains an internally located RNA structure that is required for viral replication. RNA 4: 1569–1584.

Miller LC, Blakemore W, Sheppard D, et al. (2001) Role of the cytoplasmic domain of the beta‐subunit of integrin alpha(v)beta6 in infection by foot‐and‐mouth disease virus. Journal of Virology 75: 4158–4164.

Molla A, Paul AV and Wimmer E (1991) Cell‐free, de novo synthesis of poliovirus. Science 254: 1647–1651.

Nathanson N (2008) The pathogenesis of poliomyelitis: what we don't know. Advances in Virus Research 71: 1–50.

Oberste MS, Maher K and Pallansch MA (2003) Genomic evidence that simian virus 2 and six other simian picornaviruses represent a new genus in Picornaviridae. Virology 314: 283–293.

Pacheco JM, Henry TM, O'Donnell VK, Gregory JB, Mason PW. (2003) Role of nonstructural proteins 3A and 3B in host range and pathogenicity of foot‐and‐mouth disease virus. Journal of Virology 77: 13017–13027. PMID:14645558

Patel N, Dykeman EC, Coutts RH, et al. (2015) Revealing the density of encoded functions in a viral RNA. Proceedings of the National Academy of Sciences of the United States of America 112 (7): 2227–2232. DOI: 10.1073/pnas.1420812112. PMID:25646435

Perera R, Daijogo S, Walter BL, Nguyen JH and Semler BL (2007) Cellular protein modification by poliovirus: the two faces of poly(rC)‐binding protein. Journal of Virology 81: 8919–8932.

Papageorgiou N, Coutard B, Lantez V, et al. (2010) The 2C putative helicase of echovirus 30 adopts a hexameric ring‐shaped structure. Acta Crystallographica Section D: Biological Crystallography 1116–1120. DOI: 10.1107/S090744491002809X. PMID:20944244

Pathak HB, Oh HS, Goodfellow IG, Arnold JJ and Cameron CE (2008) Picornavirus genome replication: roles of precursor proteins and rate‐limiting steps in oriI‐dependent VPg uridylylation. Journal of Biological Chemistry 283: 30677–30688.

Pevear DC, Fancher MJ, Felock PJ, et al. (1989) Conformational change in the floor of the human rhinovirus canyon blocks adsorption to HeLa cell receptors. Journal of Virology 63: 2002–2007.

Porta C, Kotecha A, Burman A, Jackson T, Ren J, Loureiro S, Jones IM, Fry EE, Stuart DI, Charleston B. (2013) Rational engineering of recombinant picornavirus capsids to produce safe, protective vaccine antigen. PLoS Pathogens 9 (3): e1003255. DOI: 10.1371/journal.ppat.1003255. PMID:23544011

Rachow A, Gauss‐Muller V and Probst C (2003) Homogeneous hepatitis A virus particles. Proteolytic release of the assembly signal 2A from procapsids by factor Xa. Journal of Biological Chemistry 278: 29744–29751.

Ren J, Wang X, Hu Z, et al. (2013) Picornavirus uncoating intermediate captured in atomic detail. Nature Communications 4: 1929. DOI: 10.1038/ncomms2889.

Reuter G, Boldizsar A, Kiss I and Pankovics P (2008) Candidate new species of Kobuvirus in porcine hosts. Emerging Infectious Diseases 14: 1968–1970.

Rossmann MG, Arnold E, Erickson JW, et al. (1985) Structure of a human common cold virus and functional relationship to other picornaviruses. Nature 317: 145–153.

Schober D, Kronenberger P, Prchla E, Blaas D and Fuchs R (1998) Major and minor receptor group human rhinoviruses penetrate from endosomes by different mechanisms. Journal of Virology 72: 1354–1364.

Smith TJ, Kremer MJ, Luo M, et al. (1986) The site of attachment in human rhinovirus 14 for antiviral agents that inhibit uncoating. Science 233: 1286–1293.

Solomon T, Lewthwaite P, Perera D et al. (2010) Virology, epidemiology, pathogenesis, and control of enterovirus 71. Lancet Infectious Diseases; 10 (11): 778–790. DOI: 10.1016/S1473‐3099(10)70194‐8. PMID:20961813

Stanway G, Joki‐Korpela P and Hyypia T (2000) Human parechoviruses–biology and clinical significance. Reviews in Medical Virology 10: 57–69.

Tseng CH, Knowles NJ and Tsai HJ (2007) Molecular analysis of duck hepatitis virus type 1 indicates that it should be assigned to a new genus. Virus Research 123: 190–203.

Tuthill TJ, Harlos K, Walter TS, et al. (2009) Equine rhinitis A virus and its low pH empty particle: clues towards an aphthovirus entry mechanism? PLoS Pathogens 5: e1000620.

Vance LM, Moscufo N, Chow M and Heinz BA (1997) Poliovirus 2C region functions during encapsidation of viral RNA. Journal of Virology 71: 8759–8765.

Venkataraman S, Reddy SP, Loo J, et al. (2008) Structure of Seneca Valley Virus‐001: an oncolytic picornavirus representing a new genus. Structure 16: 1555–1561.

Ventoso I, MacMillan SE, Hershey JW and Carrasco L (1998) Poliovirus 2A proteinase cleaves directly the eIF‐4G subunit of eIF‐4F complex. FEBS Letters 435: 79–83.

Wang X, Ren J, Gao Q, Hu Z, Sun Y, Li X, Rowlands DJ, Yin W, Wang J, Stuart DI, Rao Z, Fry EE. (2015) Hepatitis A virus and the origins of picornaviruses. Nature. 517 (7532): 85–88. PMID:25327248

Welchman Dde B, Cox WJ, Gough RE, et al. (2009) Avian encephalomyelitis virus in reared pheasants: a case study. Avian Pathology 38: 251–256.

WHO (2015) WHO polio eradication, http://www.polioeradication.org/

Yamashita T, Sakae K, Tsuzuki H, et al. (1998) Complete nucleotide sequence and genetic organization of Aichi virus, a distinct member of the Picornaviridae associated with acute gastroenteritis in humans. Journal of Virology 72: 8408–8412.

Yamashita T, Ito M, Kabashima Y, et al. (2003) Isolation and characterization of a new species of kobuvirus associated with cattle. Journal of General Virology 84: 3069–3077.

Zoll J, Erkens Hulshof S, Lanke K, et al. (2009) Saffold virus, a human Theiler's‐like cardiovirus, is ubiquitous and causes infection early in life. PLoS Pathogens 5: e1000416.

Further Reading

Ehrenfeld E, Domingo E and Roos RP (eds) (2010) The Picornaviruses. Washington, DC: ASM Press.

Groppelli E, Hogle J and Rowlands DJ (2010) Cell entry of non‐enveloped viruses: picornaviruses. Current Topics in Microbiology and Immunology 2010; 343: 43–89. DOI: 10.1007/82_2010_37. PMID:20397067

King AMQ, Adams MJ, Carstens EB and Lefkowitz EJ (2012) Ninth report of the International Committee on the Taxonomy of Viruses. Academic Press: Elsevier. ISBN:. ISBN: 9780123846846.

Mahy BWJ (ed.) (2005) Foot‐and‐mouth disease virus. Current Topics in Microbiology and Immunology, vol. 288. Berlin, Heidelberg: Springer. Picornavirus Homepage. http://picornastudygroup.com

Racaniello VR (2013) Picornaviridae: the viruses and their replication. In: Knipe DM, Howley PM, et al. (eds) Fields Virology, 6th edn. Philadelphia, PA: Lippincott‐Raven.

Rowlands DJ (ed) (2003) Foot‐and‐Mouth Disease. Virus Research, vol. 91.

Sobrino F and Domingo E (eds) (2004) Foot‐and‐Mouth Disease: Current Perspectives. Wymondham, Norfolk: Horizon Bioscience.

Zuckerman AJ, Banatvala JE and Pattison JR (eds) (2000) Principles and Practice of Clinical Virology, 4th edn. Chichester, UK: Wiley.

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Rowlands, David J(Sep 2015) Picornaviruses. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0001080.pub3]