[Animation] - Prion Diseases

Why do the changes in proteins in a prion disease not require a change in DNA?

Prions are malformed proteins. However the change is not a change in amino acid sequence but a change in conformation. The amino acid chains of prions are folded differently than the chains of the functional version of the molecule. When a prion interacts with a functional version of the protein it causes the conformation of the functional protein to change. The formerly functional protein changes its folding pattern to that of the prion. Both the original prion and the new prion can go on to change the conformation of other protein molecules. In this way the change can spread with no change in DNA.

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