Hexon protein

Carlisle RC, Bettinger T, Ogris M, Hale S, Mautner V, Seymour LW (2001) Adenovirus hexon protein enhances nuclear delivery and increases transgene expression of polyethy-lenimine/plasmid DNA vectors. Mol Ther 4 473 183... 

Fold Hexon protein 2 anti-parallel viral f) barrels with extended loops thatform the tower region... 

Perhaps the most spectacular homology seen to date is the similarity between the hexon protein of a mammalian virus, adenovirus, and the P3 coat protein of a bacteriophage PRDl, both containing two jelly-roll domains (Athappilly et al, 1994 Benson et al, 1999). This only goes to show that as our understanding of other viral proteins expands, so will the homologies that will likely become apparent. 

The adenovirus capsid is an icosahedral capsid that can be described as pseudo-T=25. The 12 pentameric vertices are each composed of 5 molecules of the penton bases, carrying a trimeric fiber. The 20 faces are composed of the 4 molecules of hexon protein, which itself is a trimer of the 967-residue-long polypeptide II. The crystal structure of the hexon has been solved and it reveals that the trimeric subunits are intimately intertwined, thus accounting for their observed stability. The capsid also... 

Blanche F, Cameron B, Somarriba S, et al. (2001). Stabilization of recombinant adenovirus Site-directed mutagenesis of key asparagine residues in the hexon protein. Anal. Biochem. 297 1-9. 

The humoral response to vector will be more difficult to overcome, since the targets for immune activation, the capsid proteins, are critical to the formation of viable vector particles. A number of investigators have attempted to characterize the epitopes on the capsid to which the neutralizirrg antibodies are directed (61-63). The predominant epitopes are located in hypervariable regions of the hexon protein that are located on the surface of the capsid shell (12). Additional neutralizing epitopes may also be found on the fiber protein. 

Crawford-MikszaL, Schnurr DP. Analysis of 15 adenovirus hexon proteins reveals the location and structure of seven hypervaiiable regions containing serotype-specific residues. J Virol 1996 70 1836-1844. 

Ostapchuk P, Hearing P. Pseudopackaging of adenovirus type 5 genomes into capsids containing the hexon proteins of adenovirus serotypes B, D, or E. J Virol 2001 75 45-51. 

---