3G7W

Islet Amyloid Polypeptide (IAPP or Amylin) Residues 1 to 22 fused to Maltose Binding Protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.170 
  • R-Value Observed: 0.171 

wwPDB Validation   3D Report Full Report


This is version 2.0 of the entry. See complete history


Literature

Atomic structures of IAPP (amylin) fusions suggest a mechanism for fibrillation and the role of insulin in the process

Wiltzius, J.J.Sievers, S.A.Sawaya, M.R.Eisenberg, D.

(2009) Protein Sci 18: 1521-1530

  • DOI: 10.1002/pro.145
  • Primary Citation of Related Structures:  
    3G7V, 3G7W

  • PubMed Abstract: 
  • Islet Amyloid Polypeptide (IAPP or amylin) is a peptide hormone produced and stored in the beta-islet cells of the pancreas along with insulin. IAPP readily forms amyloid fibrils in vitro, and the deposition of fibrillar IAPP has been correlated with the pathology of type II diabetes ...

    Islet Amyloid Polypeptide (IAPP or amylin) is a peptide hormone produced and stored in the beta-islet cells of the pancreas along with insulin. IAPP readily forms amyloid fibrils in vitro, and the deposition of fibrillar IAPP has been correlated with the pathology of type II diabetes. The mechanism of the conversion that IAPP undergoes from soluble to fibrillar forms has been unclear. By chaperoning IAPP through fusion to maltose binding protein, we find that IAPP can adopt a alpha-helical structure at residues 8-18 and 22-27 and that molecules of IAPP dimerize. Mutational analysis suggests that this dimerization is on the pathway to fibrillation. The structure suggests how IAPP may heterodimerize with insulin, which we confirmed by protein crosslinking. Taken together, these experiments suggest the helical dimerization of IAPP accelerates fibril formation and that insulin impedes fibrillation by blocking the IAPP dimerization interface.


    Organizational Affiliation

    Howard Hughes Medical Institute, UCLA-DOE Institute of Genomics and Proteomics, Los Angeles, California 90095-1570, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Maltose-binding periplasmic protein, Islet amyloid polypeptide fusion protein A393Escherichia coli K-12Homo sapiens
This entity is chimeric
Mutation(s): 3 
Gene Names: malEb4034JW3994IAPP
Find proteins for P0AEX9 (Escherichia coli (strain K12))
Explore P0AEX9 
Go to UniProtKB:  P0AEX9
Find proteins for P10997 (Homo sapiens)
Explore P10997 
Go to UniProtKB:  P10997
NIH Common Fund Data Resources
PHAROS:  P10997
Protein Feature View
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  • Reference Sequence
Oligosaccharides

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Entity ID: 2
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose
B
3 N/A Oligosaccharides Interaction
Biologically Interesting Molecules (External Reference) 1 Unique
Entity ID: 2
IDChainsNameType/Class2D Diagram3D Interactions
PRD_900009
Query on PRD_900009
Balpha-maltotrioseOligosaccharide /  Nutrient

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.170 
  • R-Value Observed: 0.171 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 84.495α = 90
b = 84.495β = 90
c = 144.292γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
BOSdata collection

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-06-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Derived calculations, Version format compliance
  • Version 1.2: 2017-08-16
    Changes: Refinement description, Source and taxonomy
  • Version 1.3: 2017-11-01
    Changes: Refinement description
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Database references, Derived calculations, Non-polymer description, Structure summary