6ZRQ image
Deposition Date 2020-07-14
Release Date 2020-09-30
Last Version Date 2025-04-09
Entry Detail
PDB ID:
6ZRQ
Keywords:
Title:
two-protofilament amyloid structure of S20G variant of human amylin (IAPP - islet amyloid polypeptide)
Biological Source:
Source Organism:
Homo sapiens (Taxon ID: 9606)
Method Details:
Experimental Method:
Resolution:
3.90 Å
Aggregation State:
FILAMENT
Reconstruction Method:
HELICAL
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Islet amyloid polypeptide
Gene (Uniprot):IAPP
Mutations:S20G
Chain IDs:A, B, C, D, E, F, G, H, I, J, K, L
Chain Length:37
Number of Molecules:12
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
Fibril structures of diabetes-related amylin variants reveal a basis for surface-templated assembly.
Nat.Struct.Mol.Biol. 27 1048 1056 (2020)
PMID: 32929282 DOI: 10.1038/s41594-020-0496-3

Abstact

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.

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Primary Citation of related structures