Hexon protein
{{distinguish||text=exon, a part of a gene, or axon, the projection of a neuron}}
{{Infobox protein family
| Symbol = Adeno_hexon
| Name = Adeno_hexon
| image = PDB 1p2z EBI.jpg
| width =
| caption = refinement of adenovirus type 2 hexon with cns
| Pfam = PF01065
| Pfam_clan =
| InterPro = IPR016107
| SMART =
| PROSITE =
| MEROPS =
| SCOP = 1dhx
| TCDB =
| OPM family =
| OPM protein =
| CAZy =
| CDD =
}}
{{Infobox protein family
| Symbol = Adeno_hexon_C
| Name = Adeno_hexon_C
| image = PDB 2bvi EBI.jpg
| width =
| caption = the quasi-atomic model of human adenovirus type 5 capsid (part 2)
| Pfam = PF03678
| Pfam_clan =
| InterPro = IPR016108
| SMART =
| PROSITE =
| MEROPS =
| SCOP = 1dhx
| TCDB =
| OPM family =
| OPM protein =
| CAZy =
| CDD =
}}
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 (holding in place a fibre), lie at each of the 12 vertices.{{cite journal | vauthors = Athappilly FK, Murali R, Rux JJ, Cai Z, Burnett RM | title = The refined crystal structure of hexon, the major coat protein of adenovirus type 2, at 2.9 A resolution | journal = Journal of Molecular Biology | volume = 242 | issue = 4 | pages = 430–55 | date = September 1994 | pmid = 7932702 | doi = 10.1006/jmbi.1994.1593 | doi-access = free }} 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.{{cite journal | vauthors = Rux JJ, Kuser PR, Burnett RM | title = Structural and phylogenetic analysis of adenovirus hexons by use of high-resolution x-ray crystallographic, molecular modeling, and sequence-based methods | journal = Journal of Virology | volume = 77 | issue = 17 | pages = 9553–66 | date = September 2003 | pmid = 12915569 | pmc = 187380 | doi = 10.1128/jvi.77.17.9553-9566.2003 }} Some hexon proteins contain a distinct C-terminal domain.
Hexon directly recruits the cellular motor protein dynein in a pH-dependent manner.{{cite journal | vauthors = Bremner KH, Scherer J, Yi J, Vershinin M, Gross SP, Vallee RB | title = Adenovirus transport via direct interaction of cytoplasmic dynein with the viral capsid hexon subunit | language = English | journal = Cell Host & Microbe | volume = 6 | issue = 6 | pages = 523–35 | date = December 2009 | pmid = 20006841 | pmc = 2810746 | doi = 10.1016/j.chom.2009.11.006 }} The dynein-regulatory protein, dynactin, was found to play a clear role in regulating the dynein-adenovirus complex transport to the nucleus.