Forms an icosahedral capsid with a T=7 symmetry and a 50 nm diameter. The capsid is composed of 72 pentamers linked to each other by disulfide bonds and associated with L2 proteins. Binds to heparan sulfate proteoglycans on the basement membrane to provide initial virion attachment to target cells. Basement membrane is exposed only after epithelium trauma. Additionally, the alpha6 integrin complexed with either beta1 or beta4 integrin has been proposed to act as a coreceptor recognized by L1. Once attached, integrin complexed with beta4 integrin has been proposed to act as a coreceptor recognized by L1. Once attached, the virion enters the host cell via clathrin-mediated endocytosis and the genomic DNA is released to the host nucleus. The virion assembly takes place within the cell nucleus. Encapsulates the genomic DNA together with protein L2.

[1] "Human papillomavirus type 16 DNA sequence."Seedorf K., Krammer G., Durst M., Suhai S., Rowekamp W.G.Virology 145:181-185(1985) [2] "Nucleotide sequences and further characterization of human papillomavirus DNA present in the CaSki, Si