page_title: Potyvirus
section_title: Virology
hierarchical_section_title: Potyvirus / Virology
caption_attribution_description: English: Potyviridae. Genomic map of a typical member of the genus Potyvirus. The ssRNA genome is represented by a line and the polyprotein ORF by an open box with the mature proteolytic products named. VPg (viral protein genome-linked), the genome-linked viral protein covalently attached to the 5′-terminal nucleotide is represented by a hexagon; P1-Pro (protein 1 protease), a protein with serine proteolytic activity responsible for cleavage at typically Tyr/Phe-Ser (O); HC-Pro (helper component protease), a protein with aphid transmission helper-component activity and cysteine proteolytic activity responsible for cleavage at typically Gly-Gly (◆); P3 (protein 3); PIPO (pretty interesting Potyviridae ORF); 6K (six kilodalton peptide); CI (cytoplasmic inclusion); NIa-Pro (nuclear inclusion A protease), cysteine-like proteolytic activity responsible for cleavage at Gln/Glu-(Ser/Gly/Ala) (↓); Nib (nuclear inclusion B), RNA-dependent RNA polymerase; CP (coat protein). Cleavage sites of P1-Pro, (O), HC-Pro (◆) and NIa-Pro (↓) are indicated.
context_page_description: Potyvirus is a genus of viruses in the family Potyviridae. Plants serve as natural hosts. There are currently 183 species in this genus including the type species Potato virus Y. The genus is named after the type virus. Potyviruses account for ~30% of the currently known plant viruses. Like begomoviruses, members of this genus may cause significant losses in agricultural, pastoral, horticultural and ornamental crops. More than 200 species of aphids spread potyviruses and most are from the subfamily Aphidinae.
context_section_description: The virion is non-enveloped with a flexuous and filamentous nucleocapsid, 680 to 900 nanometers (nm) long and is 11–20 nm in diameter. The nucleocapsid contains ~2000 copies of the capsid protein. The symmetry of the nucleocapsid is helical with a pitch of 3.4 nm.
  The genome is a linear positive sense ssRNA ranging in size from 9000–12000 bases/nucleotides. Most potyviruses have non-segmented genomes, though a number of species are bipartite. The base composition is: 21–23.51–26% G; 23–30.15–44% A; 14.9–22.41–28% C; 15.6–24.41–30.9% U. 
  In the species with a single genome, at the 5' end a protein is covalently linked (the Vg protein). It encodes a single open reading frame (ORF) expressed as a 350kDa polyprotein precursor. This is processed into seven smaller proteins: P1, helper component (HC), P3, cylindrical inclusion (CI), nuclear inclusion A (NIa), nuclear inclusion B (NIb), capsid protein (CP) and two small putative proteins known as 6K1 and 6K2. The P3 cistron also encodes a second protein—P3N-PIPO—which is generated by a +2 frameshift.
caption: Genomic map of a typical member of the genus Potyvirus.
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