Hexon protein


In molecular biology, the hexon protein is a major coat protein found in Adenoviruses. 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 penton base, 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. Some hexon proteins contain a distinct C-terminal domain.
Hexon directly recruits the cellular motor protein dynein in a pH-dependent manner. The dynein-regulatory protein, dynactin, was found to play a clear role in regulating the dynein-adenovirus complex transport to the nucleus.