Article Figures & Data
Figures
- Fig. 1.
The genome of a typical picornavirus, together with schematic maps of the polyprotein in each of the six picornavirus genera. VPg, the peptide covalently attached to the 5′ terminus of the RNA genome, is shown as a small solid square. The virus-encoded activities responsible for processing each protein boundary are indicated: vertical arrows, 3Cpro cleavages (also including those for which 3CDpro are required); arrow with circle, 2Apro, the trypsin family member found in entero- and rhinoviruses; double-headed arrow, 2A-associated cleavages in cardioviruses and aphthoviruses; barbell, Lpro of aphthoviruses. The site of VP0 (maturation) cleavage, which occurs by an unknown, possibly autocatalytic mechanism, is indicated (?). For clarity, the positions of VP4 (1A), VP2 (1B), VP3 (1C), VP1 (1D), and VP0 (1AB) are indicated on the polyprotein maps as 4, 2, 3, 1, and 0, respectively. The aphthovirus foot-and-mouth disease virus encodes three tandem copies of VPg.
- Fig. 2.
(A) Schematic representation of the predicted 5′UTR secondary structure of the parechovirus HPEV1. The structure is strikingly similar to that predicted for encephalomyocarditis virus (B), a representative of the cardio- and aphthovirus 5′UTR group; it is dissimilar from that of poliovirus (C), a representative of the entero- and rhinovirus 5′UTR group. All picornaviruses have a polypyrimidine tract (shown as a heavy line and labelled pp) about 20 nucleotides upstream of an AUG (labelled with a square). In cardio- and aphthoviruses this AUG initiates the open reading frame, while in entero- and rhinoviruses a second AUG located downstream has this function. The variable region is seen in all enteroviruses, but is largely deleted in rhinoviruses. VPg, covalently attached to the 5′ terminus, is shown as a solid circle.
- Fig. 3.
Dendrogram, based on comparisons of the VP3 protein, illustrating the genetic relationships among selected representatives of each of the picornaviruses genera. Abbreviations: HAV, hepatitis A virus; HRV, human rhinovirus; EV, enterovirus; CBV, coxsackie B virus; SVDV, swine vesicular disease virus; PV, poliovirus; EMCV, encephalomyocarditis virus; TMEV, Theiler’s murine encephalomyelitis virus; FMDV, foot-and-mouth disease virus.
