Protein of the Year: Tobacco Mosaic Virus

Source:  Protein of the Year: Tobacco Mosaic Virus    Tag:  tobacco mosaic virus treatment
A To-The-Point List of Reasons Why the Tobacco Mosaic Virus Should Be the Protein of the Year (shortened, as there are so many):

- It was the very first virus to be discovered. The very first protein to be found that acts as an infective agent! 

- It's sturdy. It can survive for years in cigarettes or cigars made from infected tobacco leaves.

- It can infect over 150 plants. 

- This infection leads to a wide range of symptoms; for grapes and apples, TMV infection is virtually inconsequential. For tobacco and tomatoes, it can ultimately lead to yellowing and malformation of leaves and fruit.

- There is no chemical cure and it can be transmitted through mere contact. This means that getting rid of TMV is a difficult endeavor, as absolutely everything that came into contact with the infected plants must be cleaned or destroyed.

- The protein component of TMV forms a coat over the viral RNA. In order for the RNA to be replicated once inside the cell, this coat must be removed. To do this, TMV takes advantage of the differing calcium concentrations outside and inside the cell. In high calcium concentrations, like outside the cell, there are several amino acid clusters that are stable. Once inside the cell, where calcium concentration is low, these same amino acid clusters repel each other. 

- TMV forms spontaneously; if you mixed the viral RNA and protein coat components together, they form fully functional viruses. 

- During formation, 34 protein components form a two-layer disk (so 17 protein components per disk). The viral RNA then recognizes and binds to a sequence in the hole of that bilayer disk,  which forces the protein into a lockwasher shape. With this shape, more protein components go into place by binding, and therefore protecting, the viral RNA. This continues until the RNA is entirely covered and protected.