3DUH

Structure of Interleukin-23


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.228 
  • R-Value Observed: 0.230 

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Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

The structure of interleukin-23 reveals the molecular basis of p40 subunit sharing with interleukin-12.

Lupardus, P.J.Garcia, K.C.

(2008) J Mol Biol 382: 931-941

  • DOI: https://doi.org/10.1016/j.jmb.2008.07.051
  • Primary Citation of Related Structures:  
    3DUH

  • PubMed Abstract: 

    Interleukin (IL)-23 is a recently identified member of the IL-12 family of heterodimeric cytokines that modulate subpopulations of T helper cells, and both IL-12 and IL-23 are attractive targets for therapy of autoimmune diseases. IL-23 is a binary complex of a four-helix bundle cytokine (p19) and a soluble class I cytokine receptor p40. IL-12 and IL-23 share p40 as an alpha-receptor subunit, yet show only 15% sequence homology between their four-helix cytokines p19 and p35, respectively, and signal through different combinations of shared receptors. In order to elucidate the structural basis of p40 sharing, we have determined a 2.3-A crystal structure of IL-23 for comparison to the previously determined structure of IL-12. The docking mode of p19 to p40 is altered compared to p35, deviating by a 'tilt' and 'roll' that results in an altered footprint of p40 on the A and D helices of the respective cytokines. Binding of p19 to p40 is mediated primarily by an arginine residue on helix D of p19 that forms an extensive charge and hydrogen-bonding network with residues at the base of a pocket on p40. This 'arginine pocket' is lined with an inner shell of hydrophobic interactions that are ringed by an outer shell of polar interactions. Comparative analysis indicates that the IL-23 and IL-12 complexes 'mimic' the network of interactions constituting the central arginine pocket despite p19 and p35 having limited sequence homology. The majority of the structural epitopes in the two complexes are composed of unique p19 and p35 pairwise contacts with common residues on p40. Thus, while the critical hotspot is maintained in the two complexes, the majority of the interfaces are structurally distinct and, therefore, provide a basis for the therapeutic targeting of IL-12 versus IL-23 heterodimer formation despite their use of a common receptor subunit.


  • Organizational Affiliation

    Howard Hughes Medical Institute, Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Interleukin-12 subunit beta
A, B
314Homo sapiensMutation(s): 0 
Gene Names: IL12BNKSF2
UniProt & NIH Common Fund Data Resources
Find proteins for P29460 (Homo sapiens)
Explore P29460 
Go to UniProtKB:  P29460
PHAROS:  P29460
GTEx:  ENSG00000113302 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP29460
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Interleukin-23 subunit alpha
C, D
177Homo sapiensMutation(s): 0 
Gene Names: IL23ASGRFUNQ2498/PRO5798
UniProt & NIH Common Fund Data Resources
Find proteins for Q9NPF7 (Homo sapiens)
Explore Q9NPF7 
Go to UniProtKB:  Q9NPF7
PHAROS:  Q9NPF7
GTEx:  ENSG00000110944 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9NPF7
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download Ideal Coordinates CCD File 
E [auth A],
F [auth B]
2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.228 
  • R-Value Observed: 0.230 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 116.089α = 90
b = 59.974β = 90.46
c = 160.365γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data collection
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-08-19
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 1.2: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Data collection, Database references, Derived calculations, Structure summary
  • Version 1.3: 2023-08-30
    Changes: Advisory, Data collection, Database references, Refinement description, Structure summary