FOOT-AND-MOUTH DISEASE VIRUS
foot-and-mouth disease virus (FMDV)
Foot-and-Mouth disease is caused by a virus and affects certain types of hoofed animals like cows. Humans can be infected with by drinking cow's milk as an example or by close contact with infected animals. The effects of the foot-and-mouth disease virus (FMDV) are not serious. Nevertheless, as with any infectious disease, proper handling of FMDV epidemics is important, because there will always be the possibility of mutations that might affect humans severely. Since FMDV is very common and highly infectious, proper care is necessary. Determining the structures of such viruses is done in the hope to find targets for drugs, that might help eliminate the virus. FMDV is a spherically shaped virus with about 300 A diameter. Its genetic material is stored in a single-stranded RNA chain. This RNA is carried inside a capsid formed by proteins. Four different types of proteins are used: VP1 to VP4 (VP = viral protein). The capsid contains 60 copies of each of them. When assembled the capsid resembles an icosahedron. Icosahedrons have 20 equilateral triangular faces and each corner of such a face is occupied by protein molecules, resulting in 60 copies.
Shown here is the assembly of the four viral proteins. This assembly occupies the corners of the triangular faces. They four proteins come together in such a way that the overall shape of the complex itself is approximately triangular shaped, thus helping with the packing of the capsid. Even though the structure shown is that of the basic building blocks which are repeated 60-fold in the complete virus, this structure was determined from the structure of crystals formed by complete virus particles. Obviously dealing with such a large structure, particularly if it contains many millions of active virus particles, is a difficult task that requires careful handling of the crystals during experiments. The goal of such studies is to find drugs which would bind to the capsid protein and deform them in such a way that they can no longer properly pack thus preventing the creation of infectious virus particles.
Protein Data Bank (PDB)
Fry, E. Acharya, R. Stuart, D.; "Methods used in the structure determination of foot-and-mouth disease virus."; Acta Crystallogr., Sect.A; (1993) 49:45-55 PubMed:8382928.
author: Arno Paehler