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-Structure paper
Title | Fibril structures of diabetes-related amylin variants reveal a basis for surface-templated assembly. |
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Journal, issue, pages | Nat Struct Mol Biol, Vol. 27, Issue 11, Page 1048-1056, Year 2020 |
Publish date | Sep 14, 2020 |
Authors | Rodrigo Gallardo / Matthew G Iadanza / Yong Xu / George R Heath / Richard Foster / Sheena E Radford / Neil A Ranson / |
PubMed Abstract | Aggregation of the peptide hormone amylin into amyloid deposits is a pathological hallmark of type-2 diabetes (T2D). While no causal link between T2D and amyloid has been established, the S20G ...Aggregation of the peptide hormone amylin into amyloid deposits is a pathological hallmark of type-2 diabetes (T2D). While no causal link between T2D and amyloid has been established, the S20G mutation in amylin is associated with early-onset T2D. Here we report cryo-EM structures of amyloid fibrils of wild-type human amylin and its S20G variant. The wild-type fibril structure, solved to 3.6-Å resolution, contains two protofilaments, each built from S-shaped subunits. S20G fibrils, by contrast, contain two major polymorphs. Their structures, solved at 3.9-Å and 4.0-Å resolution, respectively, share a common two-protofilament core that is distinct from the wild-type structure. Remarkably, one polymorph contains a third subunit with another, distinct, cross-β conformation. The presence of two different backbone conformations within the same fibril may explain the increased aggregation propensity of S20G, and illustrates a potential structural basis for surface-templated fibril assembly. |
External links | Nat Struct Mol Biol / PubMed:32929282 |
Methods | EM (helical sym.) |
Resolution | 3.6 - 4.0 Å |
Structure data | EMDB-11380, PDB-6zrf: EMDB-11382, PDB-6zrq: EMDB-11383, PDB-6zrr: |
Source |
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Keywords | PROTEIN FIBRIL / amyloid fibril type-2-diabetes hormone / amyloid fibril type-2-diabetes early-onset |