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

Experimental Data Snapshot

  • Resolution: 1.45 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.189 

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The amphibian antimicrobial peptide uperin 3.5 is a cross-alpha /cross-beta chameleon functional amyloid.

Salinas, N.Tayeb-Fligelman, E.Sammito, M.D.Bloch, D.Jelinek, R.Noy, D.Uson, I.Landau, M.

(2021) Proc Natl Acad Sci U S A 118

  • DOI: https://doi.org/10.1073/pnas.2014442118
  • Primary Citation of Related Structures:  

  • 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.

  • Organizational Affiliation

    Department of Biology, Technion - Israel Institute of Technology, Haifa 3200003, Israel.


Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
17Uperoleia mjobergiiMutation(s): 0 
Find proteins for P82042 (Uperoleia mjobergii)
Explore P82042 
Go to UniProtKB:  P82042
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP82042
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.45 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.189 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 19.7α = 90
b = 28.44β = 106.95
c = 20.32γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling
PDB_EXTRACTdata extraction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-06-26
    Type: Initial release
  • Version 1.1: 2019-12-25
    Changes: Data collection
  • Version 1.2: 2021-01-13
    Changes: Database references, Derived calculations
  • Version 1.3: 2021-01-20
    Changes: Database references