Fig. 2.

Template assistance mechanism illustrated for a single prion strain. The normal monomers (empty circles) are converted by the subunits (squares) by direct interaction at rate $\rho$. This first conformational change is reversed spontaneously at rate $\omega$, and the subunits are also degraded at rate $\delta$. The aggregates are formed of subunits, and the dynamics driving the interaction between aggregates and subunits are those of the nucleated polymerization model (similarly to Fig. 1, with subunits playing the role of monomers). The aggregates are degraded at rate $\mu$