Crystal structure of human transthyretin at pH 4.6

Experimental Data Snapshot

  • Resolution: 1.85 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.212 

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Acidic pH-induced conformational changes in amyloidogenic mutant transthyretin.

Pasquato, N.Berni, R.Folli, C.Alfieri, B.Cendron, L.Zanotti, G.

(2007) J Mol Biol 366: 711-719

  • DOI: https://doi.org/10.1016/j.jmb.2006.11.076
  • Primary Citation of Related Structures:  
    2G3X, 2G3Z, 2G4E, 2G4G, 2NOY

  • PubMed Abstract: 

    Several proteins, including transthyretin (TTR), can generate in tissues extracellular insoluble aggregates, in the form of fibrils, that are associated with pathological states known as amyloidoses. To date, more than 80 different TTR point mutations have been associated with hereditary amyloidosis in humans. In vitro, the formation of amyloid fibrils by human TTR is known to be triggered by acidic pH. We show here that, in vitro, the natural amyloidogenic I84S and the non-natural I84A TTR mutant forms exhibit a propensity to produce fibrils in an acidic medium significantly higher than that of wild-type TTR. The two mutant forms have been crystallized at both neutral and acidic pH. Their neutral pH crystal structures are very similar to that of wild-type TTR, consistent with previous evidence indicating that only minor structural changes are induced by amyloidogenic mutations. On the contrary, their crystal structures at moderately low pH (4.6) show significant conformational differences as compared to their neutral pH structures. Remarkably, such changes are not induced in wild-type TTR crystallized at low pH. The most relevant consist of the unwinding of the TTR short alpha-helix and of the change in conformation of the loop connecting the alpha-helix to beta-strand F. Only one monomer of the crystallographic dimer is affected, causing a disruption of the tetrameric symmetry. This asymmetry and a possible destabilization of the tetrameric quaternary structure of TTR may be responsible for the amyloidogenic potential of the two TTR mutant forms at low pH.

  • Organizational Affiliation

    Department of Chemistry, University of Padua, and ICTB, Section of Padua, Via Marzolo 1, 35131 Padova, Italy.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
127Homo sapiensMutation(s): 0 
Gene Names: TTRPALB
UniProt & NIH Common Fund Data Resources
Find proteins for P02766 (Homo sapiens)
Explore P02766 
Go to UniProtKB:  P02766
PHAROS:  P02766
GTEx:  ENSG00000118271 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02766
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.85 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.212 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.597α = 90
b = 85.953β = 90
c = 63.688γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
CCP4data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-01-16
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2023-10-25
    Changes: Data collection, Database references, Refinement description