Fungal prions prion domains

All fungal prion proteins have a so-called prion domain and a functional domain. The prion domain is a region of the polypeptide chain that is necessary and sufficient for prion formation and maintenance (Fig. 1 Wickner et al., 2002). For Ure2p and Sup35p, the functional domain is responsible for the cellular activity of the normal form of the protein. 

As noted above, many natively unfolded proteins become folded in the presence of an appropriate interaction partner. Fungal prion domains subscribe to this paradigm whereby the partner is itself (each other) and the interaction represents homotypic polymerization into amyloid. 

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