Figure 1

Comparison of surface exposed charge differences of HPV-5 and HPV-16 L1 capsid proteins. The model of the HPV-5 L1 monomer is overlaid on the crystal structure of HPV-16 L1. Colour in this illustration display positive (blue) and negative (red) amino acids loops of L1. To model L1 capsid protein the structure file for the HPV-16 L1 monomer, 1 DZL.pdb [13], was downloaded and used as a template to model L1-monomers for HPV-5 using SWISS MODEL http://swissmodel.expasy.org//SWISS-MODEL.html. Protein models were also ray-traced using POV-Ray http://www.povray.org/. The 3D-models of L1 protein of an alpha-papillomavirus (HPV-16) and a beta-papillomavirus (HPV-5) visualize the number of charged amino acids on one L1 capsid protein that are more than 30% exposed in the surface when grouped into a pentamer.