|Group:||Group IV ((+)ssRNA)|
A picornavirus is a virus belonging to the family Picornaviridae. Picornaviridae is a family of viruses in the order Picornavirales. Vertebrates, including humans, serve as natural hosts. There are currently 50 species in this family, divided among 29 genera. Diseases associated with this family include: paralysis (non-polio and polio-type), summer cold, meningitis, diarrhea caused by Enteroviruses; hand-foot-and-mouth disease (ulcers in mouth, hands, and feet) caused by Aphthoviruses; myocarditis caused by Cardioviruses; common cold caused by Rhinoviruses; and hepatitis caused by Hepatoviruses.  The name is derived from pico, meaning "small," and RNA, referring to the ribonucleic acid genome. Thus, "pico-rna-virus" literally means "small RNA virus."
Enteroviruses infect the enteric tract, which is reflected in their name. On the other hand, rhinoviruses infect primarily the nose and the throat. Enteroviruses replicate at 37°C, whereas rhinoviruses grow better at 33°C, as this is the lower temperature of the nose. Enteroviruses are stable under acid conditions and thus they are able to survive exposure to gastric acid. In contrast, rhinoviruses are acid-labile (inactivated or destroyed by low pH conditions) and that is the reason why rhinovirus infections are restricted to the nose and throat.
|Genus||Species (* signifies type species)||Serotypes|
|Aphthovirus||Bovine rhinitis A virus||2 types: bovine rhinitis A virus (BRAV) 1–2 (formerly bovine rhinovirus 1 & 3)|
|Bovine rhinitis B virus||1 type: bovine rhinitis B virus (BRBV) 1 (formerly bovine rhinovirus 2)|
|Equine rhinitis A virus||1 type: equine rhinitis A virus (ERAV) 1 (formerly equine rhinovirus 1)|
|Foot-and-mouth disease virus *||7 types: O, A, C, Southern African Territories (SAT) 1, SAT 2, SAT 3 and Asia 1|
|Aquamavirus||Aquamavirus A||1 type: seal aquamavirus A1 (SeAV-A1)|
|Avihepatovirus||Duck hepatitis A virus||3 types: duck hepatitis A virus (DHAV) 1–3|
|Cardiovirus||Encephalomyocarditis virus *||2 types: encephalomyocarditis virus (EMCV) 1 & EMCV-2. Note: Columbia SK virus, Maus Elberfeld virus and Mengovirus are strains of EMCV-1.|
|Theilovirus||12 types: Theiler's murine encephalomyelitis virus (TMEV), Vilyuisk human encephalomyelitis virus (VHEV), Thera virus (TRV), Saffold virus (SAFV) 1–9|
|Cosavirus||Cosavirus A||24 types: cosavirus A1 (CoSV-A1) to CoSV-A24|
|Dicipivirus||Cadicivirus A||1 type: canine picodicistrovirus 1 (CaPdV-1)|
|Enterovirus||Enterovirus A (formerly Human enterovirus A)||23 types: coxsackievirus A2 (CV-A2), CV-A3, CV-A4, CV-A5, CV-A6, CV-A7, CV-A8, CV-A10, CV-A12, CV-A14, CV-A16, enterovirus (EV) A71, EV-A76, EV-A89, EV-A90, EV-A91, EV-A92, EV-114, EV-A119, SV19, SV43, SV46 & BA13; see also coxsackie A virus|
|Enterovirus B (formerly Human enterovirus B)||60 types: coxsackievirus B1 (CV-B1), CV-B2, CV-B3, CV-B4, CV-B5 (incl. swine vesicular disease virus [SVDV]), CV-B6, CV-A9, echovirus 1 (E-1; incl. E-8), E-2, E-3, E-4, E-5, E-6, E-7, E-9 (incl. CV-A23), E-11, E-12, E-13, E-14, E-15, E-16, E-17, E-18, E-19, E-20, E-21, E-24, E-25, E-26, E-27, E-29, E-30, E-31, E-32, E-33, enterovirus B69 (EV-B69), EV-B73, EV-B74, EV-B75, EV-B77, EV-B78, EV-B79, EV-B80, EV-B81, EV-B82, EV-B83, EV-B84, EV-B85, EV-B86, EV-B87, EV-B88, EV-B93, EV-B97, EV-B98, EV-B100, EV-B101, EV-B106, EV-B107, EV-B110 & SA5; see also coxsackie B virus and echovirus|
|Enterovirus C * (formerly Human enterovirus C)||23 types: poliovirus (PV) 1, PV-2, PV-3, coxsackievirus A1 (CV-A1), CV-A11, CV-A13, CV-A17, CV-A19, CV-A20, CV-A21, CV-A22, CV-A24, EV-C95, EV-C96, EV-C99, EV-C102, EV-C104, EV-C105, EV-C109, EV-C113, EV-C116, EV-C117 & EV-118|
|Enterovirus D (formerly Human enterovirus D)||5 types: enterovirus D68 (EV-D68), EV-D70, EV-D94, EV-D111 & EV-D120|
|Enterovirus E (formerly Bovine enterovirus group A)||4 types (proposed): enterovirus E1 (EV-E1), EV-E2, EV-E3 & EV-E4|
|Enterovirus F (formerly Bovine enterovirus group B)||6 types (proposed): enterovirus F1 (EV-F1), EV-F2, EV-F3, EV-F4, EV-F5 & EV-E6|
|Enterovirus G (formerly Porcine enterovirus B)||6 types: enterovirus (EV) G1 to G6 (formerly porcine enterovirus 9–10, 14–16 and ovine enterovirus 1)|
|Enterovirus H (formerly Simian enterovirus A)||1 type: enterovirus H1 (EV-H1)|
|Enterovirus J||6 types: simian virus 6 (SV6), enterovirus J103 (EV-J103), EV-J108, EV-J112, EV-J115 and EV-J121|
|Rhinovirus A (formerly Human rhinovirus A)||77 types: human rhinovirus (HRV) A1, A2, A7, A8, A9, A10, A11, A12, A13, A15, A16, A18, A19, A20, A21, A22, A23, A24, A25, A28, A29, A30, A31, A32, A33, A34, A36, A38, A39, A40, A41, A43, A44, A45, A46, A47, A49, A50, A51, A53, A54, A55, A56, A57, A58, A59, A60, A61, A62, A63, A64, A65, A66, A67, A68, A71, A73, A74, A75, A76, A77, A78, A80, A81, A82, A85, A88, A89, A90, A94, A95, A96, A98, A100, A101, A102 and A103|
|Rhinovirus B (formerly Human rhinovirus B)||25 types: human rhinovirus (HRV) B3, B4, B5, B6, B14, B17, B26, B27, B35, B37, B42, B48, B52, B69, B70, B72, B79, B83, B84, B86, B91, B92, B93, B97 and B99|
|Rhinovirus C (formerly Human rhinovirus C)||51 types: human rhinovirus (HRV) C1–C51|
|Erbovirus||Equine rhinitis B virus *||3 types: equine rhinitis B virus (ERBV) 1–3 (formerly equine rhinovirus 2, 3 and acid-stable equine picornavirus)|
|Hepatovirus||Hepatitis A virus *||1 type: hepatitis A virus (HAV) 1|
|Kobuvirus||Aichivirus A * (formerly Aichi virus)||3 types: Aichi virus (AiV) 1, canine kobuvirus 1 (CaKV-1) & murine kobuvirus 1 (MuKV-1)|
|Aichivirus B (formerly Bovine kobuvirus)||2 types: bovine kobuvirus (BKV) 1 & ovine kobuvirus 1 (OKV-1)|
|Aichivirus C||1 type: porcine kobuvirus 1 (PKV-1)|
|Megrivirus||Melegrivirus A *||1 type: turkey hepatitis virus (THV) 1|
|Parechovirus||Human parechovirus *||14 types: human parechovirus (HPeV) 1-14|
|Ljungan virus||4 types: Ljungan virus (LV) 1–4|
|Piscevirus||Fathead minnow picornavirus||1 type: Fathead minnow picornavirus|
|Salivirus||Salivirus A||1 type: salivirus A1|
|Sapelovirus||Porcine sapelovirus * (formerly Porcine enterovirus A)||1 type: porcine sapelovirus (PSV) 1 (formerly PEV-8)|
|Simian sapelovirus||3 types: simian sapleovirus (SSV) 1–3|
|Avian sapelovirus||1 type: avian sapelovirus (ASV) 1|
|Senecavirus||Seneca Valley virus *||1 type: Seneca Valley virus (SVV) 1|
|Teschovirus||Porcine teschovirus *||13 types: porcine teschovirus (PTV) 1 to 13|
|Tremovirus||Avian encephalomyelitis virus||1 type: avian encephalomyelitis virus (AEV) 1|
Picornaviruses are non-enveloped, with an icosahedral capsid. The capsid is an arrangement of 60 protomers in a tightly packed icosahedral structure. Each protomer consists of 4 polypeptides known as VP (viral protein) 1, 2, 3 and 4. VP2 and VP4 polypeptides originate from one protomer known as VP0 that is cleaved to give the different capsid components. The icosahedral is said to have a triangulation number of 3, this means that in the icosahedral structure each of the 60 triangles that make up the capsid are split into 3 little triangles with a subunit on the corner. Depending on the type and degree of dehydration the viral particle is around 27–30 nm in diameter. The viral genome is around 2500 nm in length so we can therefore conclude that it must be tightly packaged within the capsid along with substances such as sodium ions in order to cancel out the negative charges on the RNA caused by the phosphate groups.
|Genus||Structure||Symmetry||Capsid||Genomic Arrangement||Genomic Segmentation|
Picornaviruses are classed under Baltimore's viral classification system as group IV viruses as they contain a single stranded, positive sense RNA genome. Their genome ranges between 7.1 and 8.9 kb (kilobases) in length. Like most positive sense RNA genomes, the genetic material alone is infectious; although substantially less virulent than if contained within the viral particle, the RNA can have increased infectivity when transfected into cells. The genome RNA is unusual because it has a protein on the 5' end that is used as a primer for transcription by RNA polymerase.
The genome is non-segmented and positive-sense (the same sense as mammalian mRNA, being read 5' to 3'). Unlike mammalian mRNA picornaviruses do not have a 5' cap but a virally encoded protein known as VPg. However, like mammalian mRNA, the genome does have a poly(A) tail at the 3' end. There is an un-translated region (UTR) at both ends of the picornavirus genome. The 5' UTR is usually longer, being around 500–1200 nucleotides (nt) in length, compared to that of the 3' UTR, which is around 30–650 nt. It is thought that the 5' UTR is important in translation and the 3' in negative strand synthesis; however the 5' end may also have a role to play in virulence of the virus. The rest of the genome encodes structural proteins at the 5' end and non-structural proteins at the 3' end in a single polyprotein.
The polyprotein is organised as follows: L-1ABCD-2ABC-3ABCD with each letter representing a protein, however, there are variations to this layout.
The 1A, 1B, 1C, and 1D proteins are the capsid proteins VP4, VP2, VP3, and VP1, respectively. VP0 is cleaved into VP2 and VP4 during virion maturation, after the capsid has been formed. The L, 2A, and 3C proteins are proteinases that internally cleave the polyprotein, but these roles vary between genera of picornaviruses. The 2B, 2C, and 3A proteins interfere with host cell function. The 3B protein is the VPg protein. The 3D protein is the RNA polymerase.
The viral particle binds to cell surface receptors. This causes a conformational change in the viral capsid proteins, and myristic acid are released. These acids form a pore in the cell membrane through which RNA is injected . Once inside the cell, the RNA un-coats and the (+) strand RNA genome is replicated through a double-stranded RNA intermediate that is formed using viral RDRP (RNA-Dependent RNA polymerase). Translation by host cell ribosomes is not initiated by a 5' G cap as usual, but rather is initiated by an IRES (Internal Ribosome Entry Site). The viral lifecycle is very rapid with the whole process of replication being completed on average within 8 hours. However as little as 30 minutes after initial infection, cell protein synthesis declines to almost zero output – essentially the macromolecular synthesis of cell proteins is “shut off”. Over the next 1–2 hours there is a loss of margination of chromatin and homogeneity in the nucleus, before the viral proteins start to be synthesized and a vacuole appears in the cytoplasm close to the nucleus that gradually starts to spread as the time after infection reaches around 3 hours. After this time the cell plasma membrane becomes permeable, at 4–6 hours the virus particles assemble, and can sometimes be seen in the cytoplasm. At around 8 hours the cell is effectively dead and lyses to release the viral particles.
Experimental data from single step growth-curve-like experiments have allowed scientists to look at the replication of the picornaviruses in great detail. The whole of replication occurs within the host cell cytoplasm and infection can even happen in cells that do not contain a nucleus (known as enucleated cells) and those treated with actinomycin D (this antibiotic would inhibit viral replication if this occurred in the nucleus.)
Translation takes place by -1 ribosomal frameshifting, viral initiation, and ribosomal skipping. The virus exits the host cell by lysis, and viroporins. Vertebrates serve as the natural host. Transmission routes are fecal-oral, contact, ingestion, and air borne particles.
|Genus||Host Details||Tissue Tropism||Entry Details||Release Details||Replication Site||Assembly Site||Transmission|
|Aphthovirus||Seaweed||Epithelium: soft palate; epithelium: pharynx; epithelium: lung; epithelium: feet; epithelium: mouth||Clathrin-mediated endocytosis||Lysis||Cytoplasm||Cytoplasm||Contact; saliva; aerosol|
|Cardiovirus||Humans; vertebrates||Gastrointestinal tract; CNS; heart||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Zoonosis; fomite|
|Cosavirus||Human||None||Cell receptor endocytosis||Unknown||Cytoplasm||Cytoplasm||Unknown|
|Dicipivirus||Dog||None||Cell receptor endocytosis||Unknown||Cytoplasm||Cytoplasm||Unknown|
|Enterovirus||Humans; mammals||Gastrointestinal tract||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Oral-fecal|
|Erbovirus||Horse||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Contact|
|Gallivirus||Turkey, chicken||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Hepatovirus||Humans; vertebrates||Liver||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Oral-fecal; blood|
|Hunnivirus||Cattle||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Kobuvirus||Humans||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Oral-fecal; blood|
|Kunsagivirus||Unknown||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Megrivirus||Unknown||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Mischivirus||Unknown||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Mosavirus||Unknown||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Oscivirus||Unknown||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Parechovirus||Humans||Respiratory tract; gastrointestinal tract||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Pasivirus||Pigs||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Passerivirus||Birds||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Rosavirus||Human, rodents||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Sakobuvirus||Unknown||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Salivirus||Human, chimpanzee||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Sapelovirus||Birds||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Senecavirus||Pigs, Cow||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Sicinivirus||Unknown||None||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Unknown|
|Teschovirus||Swine||Gastrointestinal tract; CNS||Cell receptor endocytosis||Lysis||Cytoplasm||Cytoplasm||Oral-fecal|
A VPg primer mechanism is utilized by the picornavirus (entero- aphtho- and others), additional virus groups (poty-, como-, calici- and others) and picornavirus-like (coronavirus, notavirus, etc.) supergroup of RNA viruses. The mechanism has been best studied for the enteroviruses (which include many human pathogens, such as poliovirus and coxsackie viruses) as well as for the aphthovirus, an animal pathogen causing foot and mouth disease (FMDV).
In this group, primer-dependent RNA synthesis utilizes a small 22–25 amino acid long viral protein linked to the genome (VPg) to initiate polymerase activity, where the primer is covalently bound to the 5’ end of the RNA template. The uridylylation occurs at a tyrosine residue at the third position of the VPg. A cis-acting replication element (CRE), which is a RNA stem loop structure, serves as a template for the uridylylation of VPg, resulting in the synthesis of VPgpUpUOH. Mutations within the CRE-RNA structure prevent VPg uridylylation, and mutations within the VPg sequence can severely diminish RdRp catalytic activity. While the tyrosine hydroxyl of VPg can prime negative-strand RNA synthesis in a CRE- and VPgpUpUOH-independent manner, CRE-dependent VPgpUpUOH synthesis is absolutely required for positive-strand RNA synthesis. CRE-dependent VPg uridylylation lowers the Km¬ of UTP required for viral RNA replication and CRE-dependent VPgpUpUOH synthesis, and is required for efficient negative-strand RNA synthesis, especially when UTP concentrations are limiting. The VPgpUpUOH primer is transferred to the 3’ end of the RNA template for elongation, which can continue by addition of nucleotide bases by RdRp. Partial crystal structures for VPgs of foot and mouth disease virus and coxsackie virus B3 suggest that there may be two sites on the viral polymerase for the small VPgs of the picornaviruses. NMR solution structures of poliovirus VPg and VPgpU show that uridylylation stabilizes the structure of the VPg, which is otherwise quite flexible in solution. The second site may be used for uridylylation, after which the VPgpU can initiate RNA synthesis. It should be noted that the VPg primers of caliciviruses, whose structures are only beginning to be revealed, are much larger than those of the picornaviruses. Mechanisms for uridylylation and priming may be quite different in all of these groups.
VPg uridylylation may include the use of precursor proteins, allowing for the determination of a possible mechanism for the location of the diuridylylated, VPg-containing precursor at the 3’ end of plus- or minus-strand RNA for production of full-length RNA. Determinants of VPg uridylylation efficiency suggest formation and/or collapse or release of the uridylylated product as the rate-limiting step in vitro depending upon the VPg donor employed. Precursor proteins also have an effect on VPg-CRE specificity and stability. The upper RNA stem loop, to which VPg binds, has a significant impact on both retention, and recruitment, of VPg and Pol. The stem loop of CRE will partially unwind, allowing the precursor components to bind and recruit VPg and Pol4. The CRE loop has a defined consensus sequence to which the initiation components bind, however; there is no consensus sequence for the supporting stem, which suggests that only the structural stability of the CRE is important.
Assembly and organization of the picornavirus VPg ribonucleoprotein complex.
- Step 1: Two 3CD (VPg complex) molecules bind to CRE with the 3C domains (VPg domain) contacting the upper stem and the 3D domains (VPg domain) contacting the lower stem.
- Step 2: The 3C dimer opens the RNA stem by forming a more stable interaction with single strands forming the stem.
- Step 3: 3Dpol is recruited to and retained in this complex by a physical interaction between the back of the thumb subdomain of 3Dpol and a surface of one or both 3C subdomains of 3CD.
VPg may also play an important role in specific recognition of viral genome by movement protein (MP). Movement proteins are non-structural proteins encoded by many, if not all, plant viruses to enable their movement from one infected cell to neighboring cells. MP and VPg interact to provide specificity for the transport of viral RNA from cell to cell. To fulfill energy requirements, MP also interacts with P10, which is a cellular ATPase.
In 1897, foot-and-mouth disease virus (FMDV), the first animal virus, was discovered. FMDV is the prototypic member of the Aphthovirus genus in the Picornaviridae family. The plaque assay was developed using poliovirus. Both RNA dependent RNA polymerase and polyprotein synthesis were discovered by studying poliovirus infected cells.
The plant-infecting picorna-like viruses have a number of properties that are distinct from the animal viruses. They have been classified into the family Secoviridae containing the subfamily Comovirinae (genera Comovirus, Fabavirus and Nepovirus), and genera Sequivirus, Waikavirus, Cheravirus, Sadwavirus, and Torradovirus (type species Tomato torrado virus)).
A number of picorna-like viruses have been described infecting insects. These include Perina nuda picorna-like virus of the tussock moth, infectious flacherie virus of the silkworm and Sacbrood virus of the honeybee, Plautia stali intestine virus kelp fly virus, Ectropis obliqua picorna-like virus, deformed wing virus, acute bee paralysis virus, Drosophila C virus, Rhopalosiphum padi virus, and Himetobi P virus. Several have been placed in a separate family—the Dicistroviridae. Others have been placed into a new family Iflaviridae. This family includes Infectious flacherie virus and SeIV-1 virus. Another virus is Nora virus from Drosophila melanogaster. This latter virus awaits further classification.
- "Viral Zone". ExPASy. Retrieved 15 June 2015.
- ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015.
- Mettenleiter TC and Sobrino F (editors). (2008). Animal Viruses: Molecular Biology. Caister Academic Press. ISBN 978-1-904455-22-6. .
- Lau SK, Woo PC, Lai KK, Huang Y, Yip CC, Shek CT, Lee P, Lam CS, Chan KH, Yuen KY (2011) Complete genome analysis of three novel picornaviruses from diverse bat species. J Virol.
- Martinez-Salas et al. (2008). "Foot-and-Mouth Disease Virus". Animal Viruses: Molecular Biology. Caister Academic Press. ISBN 978-1-904455-22-6.
- Acheson, Nicholas H (2011). Fundamentals of Molecular Virology,2e. John Wiley & Sons, Inc. ISBN 978-0470900598.
- Flanegan, JB; Baltimore, D (September 1977). "Poliovirus-specific primer-dependent RNA polymerase able to copy poly(A)". Proc. Natl. Acad. Sci. U.S.A. 74 (9): 3677–80. Bibcode:1977PNAS...74.3677F. doi:10.1073/pnas.74.9.3677. PMC 431685. PMID 198796.
- Ambros V, Baltimore D (August 1978). "Protein is linked to the 5' end of poliovirus RNA by a phosphodiester linkage to tyrosine". J. Biol. Chem. 253 (15): 5263–6. PMID 209034.
- Gu C, Zeng T, Li Y, Xu Z, Mo Z, Zheng C (October 2009). "Structure-function analysis of mutant RNA-dependent RNA polymerase complexes with VPg". Biochemistry Mosc. 74 (10): 1132–41. doi:10.1134/S0006297909100095. PMID 19916926.
- Steil BP, Barton DJ (October 2008). "Poliovirus cis-Acting Replication Element-Dependent VPg Uridylylation Lowers the Km of the Initiating Nucleoside Triphosphate for Viral RNA Replication". J. Virol. 82 (19): 9400–8. doi:10.1128/JVI.00427-08. PMC 2546976. PMID 18653453.
- Ferrer-Orta C, Arias A, Agudo R, Pérez-Luque R, Escarmís C, Domingo E, Verdaguer N (February 2006). "The structure of a protein primer-polymerase complex in the initiation of genome replication". EMBO J. 25 (4): 880–8. doi:10.1038/sj.emboj.7600971. PMC 1383552. PMID 16456546.
- Gruez A, Selisko B, Roberts M, Bricogne G, Bussetta C, Jabafi I, Coutard B, De Palma AM, Neyts J, Canard B (October 2008). "The crystal structure of coxsackievirus B3 RNA-dependent RNA polymerase in complex with its protein primer VPg confirms the existence of a second VPg binding site on Picornaviridae polymerases". J. Virol. 82 (19): 9577–90. doi:10.1128/JVI.00631-08. PMC 2546979. PMID 18632861.
- Schein CH, Oezguen N, Volk DE, Garimella R, Paul A, Braun W (July 2006). "NMR structure of the viral peptide linked to the genome (VPg) of poliovirus". Peptides 27 (7): 1676–84. doi:10.1016/j.peptides.2006.01.018. PMC 1629084. PMID 16540201.
- Schein CH, Oezguen N, van der Heden van Noort GJ, Filippov DV, Paul A, Kumar E, Braun W (August 2010). "NMR solution structure of poliovirus uridylyated peptide linked to the genome (VPgpU)". Peptides 31 (8): 1441–8. doi:10.1016/j.peptides.2010.04.021. PMC 2905501. PMID 20441784.
- Schein CH, Volk DE, Oezguen N, Paul A (June 2006). "Novel, structure-based mechanism for uridylylation of the genome-linked peptide (VPg) of picornaviruses". Proteins 63 (4): 719–26. doi:10.1002/prot.20891. PMID 16498624.
- Leen EN, Kwok KY, Birtley JR, Simpson PJ, Subba-Reddy CV, Chaudhry Y, Sosnovtsev SV, Green KY, Prater SN, Tong M, Young JC, Chung LM, Marchant J, Roberts LO, Kao CC, Matthews S, Goodfellow IG, Curry S (May 2013). "Structures of the Compact Helical Core Domains of Feline Calicivirus and Murine Norovirus VPg Proteins". J. Virol. 87 (10): 5318–30. doi:10.1128/JVI.03151-12. PMC 3648151. PMID 23487472.
- Pathak HB, Oh HS, Goodfellow IG, Arnold JJ, Cameron CE (November 2008). "Picornavirus Genome Replication: ROLES OF PRECURSOR PROTEINS AND RATE-LIMITING STEPS IN oriI-DEPENDENT VPg URIDYLYLATION". J. Biol. Chem. 283 (45): 30677–88. doi:10.1074/jbc.M806101200. PMC 2576561. PMID 18779320.
- Shen M, Wang Q, Yang Y, Pathak HB, Arnold JJ, Castro C, Lemon SM, Cameron CE (November 2007). "Human Rhinovirus Type 14 Gain-of-Function Mutants for oriI Utilization Define Residues of 3C(D) and 3Dpol That Contribute to Assembly and Stability of the Picornavirus VPg Uridylylation Complex". J. Virol. 81 (22): 12485–95. doi:10.1128/JVI.00972-07. PMC 2169002. PMID 17855535.
- Yang Y, Rijnbrand R, McKnight KL, Wimmer E, Paul A, Martin A, Lemon SM (August 2002). "Sequence Requirements for Viral RNA Replication and VPg Uridylylation Directed by the Internal cis-Acting Replication Element (cre) of Human Rhinovirus Type 14". J. Virol. 76 (15): 7485–94. doi:10.1128/JVI.76.15.7485-7494.2002. PMC 136355. PMID 12097561.
- Roy Chowdhury S, Savithri HS (2011). Pfeffer, Sebastien, ed. "Interaction of Sesbania Mosaic Virus Movement Protein with VPg and P10: Implication to Specificity of Genome Recognition". PLoS ONE 6 (1): e15609. doi:10.1371/journal.pone.0015609. PMC 3016346. PMID 21246040.
- Wu CY, Lo CF, Huang CJ, Yu HT, Wang CH (2002) The complete genome sequence of Perina nuda picorna-like virus, an insect-infecting RNA virus with a genome organization similar to that of the mammalian picornaviruses. Virology 294(2):312–323
- Sasaki J, Nakashima N, Saito H, Noda H (1998) An insect picorna-like virus, Plautia stali intestine virus, has genes of capsid proteins in the 3' part of the genome. Virology 244(1):50–58
- Hartley CJ, Greenwood DR, Gilbert RJ, Masoumi A, Gordon KH, Hanzlik TN, Fry EE, Stuart DI, Scotti PD (2005) Kelp fly virus: a novel group of insect picorna-like viruses as defined by genome sequence analysis and a distinctive virion structure. J Virol 79(21):13385–13398
- Wang X, Zhang J, Lu J, Yi F, Liu C, Hu Y. Sequence analysis and genomic organization of a new insect picorna-like virus, Ectropis obliqua picorna-like virus, isolated from Ectropis obliqua. J Gen Virol 85(Pt 5):1145–1151
- Mingxiao M, Ming L, Jian C, Song Y, Shude W, Pengfei L (2011) Molecular and biological characterization of Chinese sacbrood virus LN isolate. Comp Funct Genomics 2011:409386.
- Govan VA, Leat N, Allsopp M, Davison S (2000) Analysis of the complete genome sequence of acute bee paralysis virus shows that it belongs to the novel group of insect-infecting RNA viruses. Virology 277(2):457–463
- Millán-Leiva A, Jakubowska AK, Ferré J, Herrero S (2011) Genome sequence of SeIV-1, a novel virus from the Iflaviridae family infective to Spodoptera exigua. J Invertebr Pathol
- "Picornaviridae". Medical Subject Headings (MeSH). National Library of Medicine. Retrieved 2007-09-03.
- "Picornavirus". The Pirbright Institute. Retrieved 2007-09-03.
- Büchen-Osmond, C., ed. (2006). "ICTVdB—The Universal Virus Database, version 4". Columbia University, New York, USA.
- Kahn, Cynthia M.; Line, Scott, eds. (2005-02-08). "Porcine Enteroviral Encephalomyelitis". The Merck Veterinary Manual (9th ed.). Merck. ISBN 0-911910-50-6.
- ICTV International Committee on Taxonomy of Viruses Master Species Lists
- ICTV International Committee on Taxonomy of Viruses (official site)
- Picornaviruses—description, replication, disease
- Picornaviruses in NCBI Taxonomy browser
- Picornaviridae classification by the International Committee on Taxonomy of Viruses
- Animal viruses
- Viralzone: Picornaviridae
- Virus Pathogen Database and Analysis Resource (ViPR): Picornaviridae