1Q4V

CRYSTAL STRUCTURE OF ALLO-ILEA2-INSULIN, AN INACTIVE CHIRAL ANALOGUE: IMPLICATIONS FOR THE MECHANISM OF RECEPTOR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.219 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Crystal structure of allo-Ile(A2)-insulin, an inactive chiral analogue: implications for the mechanism of receptor binding.

Wan, Z.L.Xu, B.Chu, Y.C.Katsoyannis, P.G.Weiss, M.A.

(2003) Biochemistry 42: 12770-12783

  • DOI: https://doi.org/10.1021/bi034430o
  • Primary Citation of Related Structures:  
    1Q4V

  • PubMed Abstract: 

    The crystal structure of an inactive chiral analogue of insulin containing nonstandard substitution allo-Ile(A2) is described at 2.0 A resolution. In native insulin, the invariant Ile(A2) side chain anchors the N-terminal alpha-helix of the A-chain to the hydrophobic core. The structure of the variant protein was determined by molecular replacement as a T(3)R(3) zinc hexamer. Whereas respective T- and R-state main-chain structures are similar to those of native insulin (main-chain root-mean-square deviations (RMSD) of 0.45 and 0.54 A, respectively), differences in core packing are observed near the variant side chain. The R-state core resembles that of the native R-state with a local inversion of A2 orientation (core side chain RMSD 0.75 A excluding A2); in the T-state, allo-Ile(A2) exhibits an altered conformation in association with the reorganization of the surrounding side chains (RMSD 0.98 A). Surprisingly, the core of the R-state is similar to that observed in solution nuclear magnetic resonance (NMR) studies of an engineered T-like monomer containing the same chiral substitution (allo-Ile(A2)-DKP-insulin; Xu, B., Hua, Q. X., Nakagawa, S. H., Jia, W., Chu, Y. C., Katsoyannis, P. G., and Weiss, M. A. (2002) J. Mol. Biol. 316, 435-441). Simulation of NOESY spectra based on crystallographic protomers enables the analysis of similarities and differences in solution. The different responses of the T- and R-state cores to chiral perturbation illustrates both their intrinsic plasticity and constraints imposed by hexamer assembly. Although variant T- and R-protomers retain nativelike protein surfaces, the receptor-binding activity of allo-Ile(A2)-insulin is low (2% relative to native insulin). This seeming paradox suggests that insulin undergoes a change in conformation to expose Ile(A2) at the hormone-receptor interface.


  • Organizational Affiliation

    Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.


Macromolecules

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Insulin
A, C
21N/AMutation(s): 1 
UniProt & NIH Common Fund Data Resources
Find proteins for P01308 (Homo sapiens)
Explore P01308 
Go to UniProtKB:  P01308
PHAROS:  P01308
GTEx:  ENSG00000254647 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01308
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Insulin
B, D
30N/AMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P01308 (Homo sapiens)
Explore P01308 
Go to UniProtKB:  P01308
PHAROS:  P01308
GTEx:  ENSG00000254647 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01308
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
IIL
Query on IIL
A, C
L-PEPTIDE LINKINGC6 H13 N O2ILE
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.219 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 80.487α = 90
b = 80.487β = 90
c = 37.939γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
CNSrefinement
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-08-19
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2023-08-16
    Changes: Data collection, Database references, Derived calculations, Refinement description