9xbp

Cryo-EM structure of Sup35NM S17R fibril formed at 4 degrees (S17R4C)

spinqualitylabelsall models 9xbp, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 9xbp is a 5 chain structure with sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 2.2Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ERF3_YEAST Involved in translation termination. Stimulates the activity of ERF1. Binds guanine nucleotides. Recruited by polyadenylate-binding protein PAB1 to poly(A)-tails of mRNAs. Interaction with PAB1 is also required for regulation of normal mRNA decay through translation termination-coupled poly(A) shortening. Publication Abstract from PubMed In the [ PSI (+) ] prion system, the yeast prion protein Sup35 can form structurally distinct amyloid fibrils that lead to distinct transmissible prion states, or strains. However, our understanding of how different Sup35 fibril structures arise and translate to phenotypic variations is limited. Here, using cryo-EM and single-monomer force spectroscopy with optical tweezers, we reveal the structural basis of yeast prion propagation in four wild-type and S17R mutant variants of Sup35 that underlie different [ PSI (+) ] strains. Cryo-EM structures show that the four variants form strikingly distinct fibril structures, which exhibit varying stability and chaperone-accessibility. Force spectroscopy suggests the different distinct fibril structures are derived from distinct monomer conformational ensembles. Further, cryo-EM structures indicate that prion strain strength is correlated with enhanced fibril propagation caused by a combination of low fibril stability and a large separation between the Sup35 fibril core and the Ssa1/Sis1 chaperone-binding region. These results provide a structure-based mechanism for the yeast prion strain phenomenon with implications for understanding amyloid propagation in human neurodegenerative diseases. How Sup35 monomer conformation and amyloid fibril polymorphism determine yeast strain phenotypes.,Tanaka M, Nomura T, Boyer D, Komi Y, Ge P, Maillard RA, Rodriguez P, Yamagata A, Shirouzu M, Legname G, Samori B, Eisenberg D Res Sq [Preprint]. 2025 Nov 3:rs.3.rs-7945345. doi: 10.21203/rs.3.rs-7945345/v1. PMID:41282265 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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