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Updated: Jun 11, 2026

High-throughput Screening for Protein-based Inheritance in S. cerevisiae
Published on: August 8, 2017
The mechanism of prion inhibition by HET-S
Jason Greenwald1, Carolin Buhtz, Christiane Ritter
1Laboratory of Physical Chemistry, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland.
Abstract:
HET-S (97% identical to HET-s) has an N-terminal globular domain that exerts a prion-inhibitory effect in cis on its own prion-forming domain (PFD) and in trans on HET-s prion propagation. We show that HET-S fails to form fibrils in vitro and that it inhibits HET-s PFD fibrillization in trans. In vivo analyses indicate that beta-structuring of the HET-S PFD is required for HET-S activity. The crystal structures of the globular domains of HET-s and HET-S are highly similar, comprising a helical fold, while NMR-based characterizations revealed no differences in the conformations of the PFDs. We conclude that prion inhibition is not encoded by structure but rather in stability and oligomerization properties: when HET-S forms a prion seed or is incorporated into a HET-s fibril via its PFD, the beta-structuring in this domain induces a change in its globular domain, generating a molecular species that is incompetent for fibril growth.
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