6GS3

Crystal Structure of the Uperin-3.5 peptide from Uperoleia mjobergii forming cross-alpha fibril

Summary for 6GS3

• Entry DOI: 10.2210/pdb6gs3/pdb
• Descriptor: Uperin-3.5, THIOCYANATE ION, POTASSIUM ION, ... (4 entities in total)
• Functional Keywords: cross-alpha, fibril, amyloid-like, mating alpha-helical sheets, protein fibril
• Biological source: Uperoleia mjobergii (Mjoberg's toadlet)
• Total number of polymer chains: 2
• Total formula weight: 3704.62

Authors

Landau, M.,Tayeb-Fligelman, E.,Uson, I. (deposition date: 2018-06-13, release date: 2019-06-26, Last modification date: 2024-05-15)

Primary citation

Salinas, N.,Tayeb-Fligelman, E.,Sammito, M.D.,Bloch, D.,Jelinek, R.,Noy, D.,Uson, I.,Landau, M.
The amphibian antimicrobial peptide uperin 3.5 is a cross-alpha /cross-beta chameleon functional amyloid.
Proc.Natl.Acad.Sci.USA, 118:-, 2021

PubMed Abstract: Antimicrobial activity is being increasingly linked to amyloid fibril formation, suggesting physiological roles for some human amyloids, which have historically been viewed as strictly pathological agents. This work reports on formation of functional cross-α amyloid fibrils of the amphibian antimicrobial peptide uperin 3.5 at atomic resolution, an architecture initially discovered in the bacterial PSMα3 cytotoxin. The fibrils of uperin 3.5 and PSMα3 comprised antiparallel and parallel helical sheets, respectively, recapitulating properties of β-sheets. Uperin 3.5 demonstrated chameleon properties of a secondary structure switch, forming mostly cross-β fibrils in the absence of lipids. Uperin 3.5 helical fibril formation was largely induced by, and formed on, bacterial cells or membrane mimetics, and led to membrane damage and cell death. These findings suggest a regulation mechanism, which includes storage of inactive peptides as well as environmentally induced activation of uperin 3.5, via chameleon cross-α/β amyloid fibrils.

PubMed: 33431675
DOI: 10.1073/pnas.2014442118

Experimental method

X-RAY DIFFRACTION (1.45 Å)