7QV5

Amyloid fibril from the antimicrobial peptide uperin 3.5

Summary for 7QV5

• Entry DOI: 10.2210/pdb7qv5/pdb
• EMDB information: 14167
• Descriptor: Uperin-3.5 (1 entity in total)
• Functional Keywords: antimicrobial peptide, amyloid, filament, cross-beta, protein fibril
• Biological source: Uperoleia mjobergii (Mjoberg's toadlet)
• Total number of polymer chains: 27
• Total formula weight: 48118.89

Authors

Buecker, R.,Seuring, C.,Cazey, C.,Veith, K.,Garcia-Alai, M.,Gruenewald, K.,Landau, M. (deposition date: 2022-01-19, release date: 2022-06-29, Last modification date: 2022-08-10)

Primary citation

Bucker, R.,Seuring, C.,Cazey, C.,Veith, K.,Garcia-Alai, M.,Grunewald, K.,Landau, M.
The Cryo-EM structures of two amphibian antimicrobial cross-beta amyloid fibrils.
Nat Commun, 13:4356-4356, 2022

PubMed Abstract: The amyloid-antimicrobial link hypothesis is based on antimicrobial properties found in human amyloids involved in neurodegenerative and systemic diseases, along with amyloidal structural properties found in antimicrobial peptides (AMPs). Supporting this hypothesis, we here determined the fibril structure of two AMPs from amphibians, uperin 3.5 and aurein 3.3, by cryogenic electron microscopy (cryo-EM), revealing amyloid cross-β fibrils of mated β-sheets at atomic resolution. Uperin 3.5 formed a 3-blade symmetrical propeller of nine peptides per fibril layer including tight β-sheet interfaces. This cross-β cryo-EM structure complements the cross-α fibril conformation previously determined by crystallography, substantiating a secondary structure switch mechanism of uperin 3.5. The aurein 3.3 arrangement consisted of six peptides per fibril layer, all showing kinked β-sheets allowing a rounded compactness of the fibril. The kinked β-sheets are similar to LARKS (Low-complexity, Amyloid-like, Reversible, Kinked Segments) found in human functional amyloids.

PubMed: 35896552
DOI: 10.1038/s41467-022-32039-z

Experimental method

ELECTRON MICROSCOPY (3 Å)