Fig. 7: Model of σNS oligomerization, RNA binding, and RNA unfolding.
From: Structure of orthoreovirus RNA chaperone σNS, a component of viral replication factories
The flexible N-terminal arms of σNS are required for RNA chaperone activity, consistent with an entropy-transfer model for RNA chaperones. The free N-terminal arms of σNS oligomers exist in equilibrium between an open state that can initiate RNA binding and a closed state that engages in domain-swapping interactions and RNA release from the N-terminal arm. The dynamics of the N-terminal arms allow for the recruitment of free σNS dimers to elongate σNS oligomers to coat the RNA and enhance RNA unfolding.
