Hepatitis B Virus Architecture II
Detail of the structure of the hepatitis B virus core.
Hepatitis B Virus
Hepatitis B Virus is a very serious pathogen that infects the liver causing jaundice and occasionally death due to liver failure. Infection over longer periods of time leads to cirrhosis and sometimes cancer of the liver.

The virus is transmitted in bodily fluids and is particularly prevalent among injecting drug-users who share needles.

Virus Architecture
Viruses have small genomes that contain all of the instructions for making copies of themselves. They have evolved to be very efficient. Many viruses have a spherical protective coat (capsid) that has 'icosahedral' symmetry. An icosahedron is a 20 sided polyhedron made up of triangular faces. These structures are not only economical they are also very strong.

The architect and designer Richard Buckminster Fuller discovered the benefits of icosahedral geometry and applied it in his geodesic domes, which are a robust and lightweight form of building. Viruses evolved this technology millions of years ago.

Image Credits
HBV crystal structure: S.A Wynne, R.A. Crowther and A.G.W. Leslie, MRC Laboratory of Molecular Biology, Cambridge.

© 2007 D. Bhella/M. Robertson Molecular Machines/MRC