Molecule of the Month: Tobacco Mosaic Virus
A cylindrical arrangement of proteins protects a long strand of RNA in TMV
A Helical Virus
Exploring the Structure
Tobacco Mosaic Virus (PDB entry 2tmv)
PDB entries 2tmv and 2om3 include both the protein and the RNA in an infectious TMV particle. The illustration shown here includes only 17 subunits, along with RNA that is bound to them. Notice how the RNA is bound in a groove in the protein near the center of the ring. Three nucleotides bind to each protein subunit. The image on the right shows the clusters of acidic amino acids (bright red) that are important for disassembly of the virus inside infected cells. You can click on the illustration for an interactive Jmol version. For a closer look at these acidic amino acids, take a look at the page at Proteopedia.
Topics for Further Discussion
- Most of the viruses in the PDB are composed of a spherical shell of capsid proteins. Can you find other examples of cylindrical viruses like TMV?
- Purified TMV particles are all a very uniform 300 nanometers in length. What aspects of the structure would limit the length of assembling TMV particles?
Related PDB-101 Resources
- Browse Viruses
- Browse Nobel Prizes and PDB structures
- H. Wang, A. Planchart and G. Stubbs (1998) Caspar carboxylates: the structural basis of tobamovirus disassembly. Biophysical Journal 74, 633-638.
- D. J. Lewandowski and W. O. Dawson (1998) Tobamoviruses. In Encyclopedia of Virology, second edition, volume 3, edited by A. Granoff and R. G. Webster, Academic Press, pages 1780-1783.
- G. Stubbs (1999) Tobacco mosaic virus particle structure and the initiation of disassembly. Philosophical Transactions of the Royal Society of London B 354, 551-557
- B. D. Harrison and T. M. A. Wilson (1999) Milestones in the research on tobacco mosaic virus. Philosophical Transactions of the Royal Society of London B 354, 521-529.
- A. Klug (1999) The tobacco mosaic virus particle: structure and assembly. Philosophical Transactions of the Royal Society of London B 354, 531-535.
January 2009, David Goodselldoi:10.2210/rcsb_pdb/mom_2009_1