The viral particle must be metastable so that interactions can be reversed readily when entering and uncoating a new host cell.
These were plants where the genetic material originated in sexually compatible plants (cisgenic), plants that used physical barriers to prevent the target pest from attaching itself, and plants expressing viral coat proteins to protect against virus infection.
Viral capsids are often composed of multiples of 60 proteins.
These have in turn been subsumed under the new order Tymovirales along with the old family Tymoviridae by the International Committee on Taxonomy of Viruses based on molecular phylogenetic systematic analyses of proteins (RNA polymerase and viral coat).
There are five or more proteins in the capsid: gp8 (the major capsid protein); gp6, gp7 and gp8 (minor capsid proteins); and gp3 which acts as the initial host binding protein.
RNA2 encodes protein α, a viral capsid protein precursor, which is auto-cleaved into two mature proteins, a 38 kDa β protein and a 5 kDa γ protein, at a conserved Asn/Ala site during virus assembly.
It contains 2 overlapping open reading frames (ORF)—gag and pol—which respectively encode the capsid protein and the RNA-dependent RNA polymerase.
These open reading frames (ORFs) code for a capsid protein (CP) and an RNA-dependent RNA polymerase (RDRP).