4RAL

Crystal structure of insulin degrading enzyme in complex with macrophage inflammatory protein 1 beta


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.15 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.192 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structures of human CCL18, CCL3, and CCL4 reveal molecular determinants for quaternary structures and sensitivity to insulin-degrading enzyme.

Liang, W.G.Ren, M.Zhao, F.Tang, W.J.

(2015) J Mol Biol 427: 1345-1358

  • DOI: https://doi.org/10.1016/j.jmb.2015.01.012
  • Primary Citation of Related Structures:  
    3TN2, 4MHE, 4RA8, 4RAL

  • PubMed Abstract: 

    CC chemokine ligands (CCLs) are 8- to 14-kDa signaling proteins involved in diverse immune functions. While CCLs share similar tertiary structures, oligomerization produces highly diverse quaternary structures that protect chemokines from proteolytic degradation and modulate their functions. CCL18 is closely related to CCL3 and CCL4 with respect to both protein sequence and genomic location, yet CCL18 has distinct biochemical and biophysical properties. Here, we report a crystal structure of human CCL18 and its oligomerization states in solution based on crystallographic and small-angle X-ray scattering analyses. Our data show that CCL18 adopts an α-helical conformation at its N-terminus that weakens its dimerization, explaining CCL18's preference for the monomeric state. Multiple contacts between monomers allow CCL18 to reversibly form a unique open-ended oligomer different from those of CCL3, CCL4, and CCL5. Furthermore, these differences hinge on proline 8, which is conserved in CCL3 and CCL4 but is replaced by lysine in human CCL18. Our structural analyses suggest that a mutation of proline 8 to alanine stabilizes a type 1 β-turn at the N-terminus of CCL4 to prevent dimerization but prevents dimers from making key contacts with each other in CCL3. Thus, the P8A mutation induces depolymerization of CCL3 and CCL4 by distinct mechanisms. Finally, we used structural, biochemical, and functional analyses to unravel why insulin-degrading enzyme degrades CCL3 and CCL4 but not CCL18. Our results elucidate the molecular basis for the oligomerization of three closely related CC chemokines and suggest how oligomerization shapes CCL chemokine function.


  • Organizational Affiliation

    Ben May Department for Cancer Research, The University of Chicago, IL 60637, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Insulin-degrading enzyme
A, B
990Homo sapiensMutation(s): 14 
Gene Names: IDE
EC: 3.4.24.56
UniProt & NIH Common Fund Data Resources
Find proteins for P14735 (Homo sapiens)
Explore P14735 
Go to UniProtKB:  P14735
PHAROS:  P14735
GTEx:  ENSG00000119912 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP14735
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
C-C motif chemokine 4C [auth D],
D [auth E]
69Homo sapiensMutation(s): 0 
Gene Names: CCL4LAG1MIP1BSCYA4
UniProt & NIH Common Fund Data Resources
Find proteins for P13236 (Homo sapiens)
Explore P13236 
Go to UniProtKB:  P13236
PHAROS:  P13236
GTEx:  ENSG00000275302 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP13236
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.15 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.192 
  • Space Group: P 65
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 263.117α = 90
b = 263.117β = 90
c = 90.85γ = 120
Software Package:
Software NamePurpose
HKL-3000data collection
PHASESphasing
PHENIXrefinement
HKL-3000data reduction
HKL-3000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-05-13
    Type: Initial release
  • Version 1.1: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description