| Type: | Domain | Name: | Hexon coat protein, subdomain 4 |
| Description: | Hexon is a major coat protein found in various species-specific Adenoviruses, which are type II dsDNA viruses. Hexon coat proteins are synthesised during late infection and form homo-trimers. The 240 copies of the hexon trimer that are produced are organised so that 12 lie on each of the 20 facets. The central 9 hexons in a facet are cemented together by 12 copies of polypeptide IX. The penton complex, formed by the peripentonal hexons and base hexon (holding in place a fibre), lie at each of the 12 vertices []. The hexon coat protein is a duplication consisting of two domains with a similar fold packed together like the nucleoplasmin subunits. Within a hexon trimer, the domains are arranged around a pseudo 6-fold axis. The domains have a beta-sandwich structure consisting of 8 strands in two sheets with a jelly-roll topology; each domain is heavily decorated with many insertions [].The Adenovirus major capsid proteins share a similar structure to those (vp54 and vp72) found in Iridoviruses, Phycodnaviruses, Asfarviruses and Ascoviruses, which are all type II dsDNA viruses with no RNA stage. In these viruses, vp54/vp72 is the most abundant structural protein and can account for up to 45% of virion protein []. The structure of vp54 has been determined from Paramecium bursaria Chlorella virus 1(PBCV-1), a very large icosahedral virus containing an internal membrane enclosed within a glycoprotein coat. The vp54 protein is a duplication consisting of two domains with a similar fold packed together like the nucleoplasmin subunits. The vp54 protein forms a trimer, where the domains are arranged around a pseudo 6-fold axis. The domains have a beta-sandwich structure consisting of 8 strands in two sheets with a jelly-roll topology [].This entry represents a structural subdomain with a distorted beta-sandwich topology that is found in Adenovirus hexon coat proteins, as well as the vp54/vp72 major coat proteins of Iridoviruses, Phycodnaviruses, Asfarviruses and Ascoviruses. | Short Name: | Hexon_subdom4 |
