3NFP

Crystal structure of the Fab fragment of therapeutic antibody daclizumab in complex with IL-2Ra (CD25) ectodomain


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.86 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.253 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural basis of immunosuppression by the therapeutic antibody daclizumab

Yang, H.Wang, J.Du, J.Zhong, C.Zhang, D.Guo, H.Guo, Y.Ding, J.

(2010) Cell Res. 20: 1361-1371

  • DOI: 10.1038/cr.2010.130
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Interleukin-2 (IL)-2 signaling plays a pivotal role in the activation of immune responses, and drugs that block this pathway have been shown to be effective for the immunosuppression in patients with organ transplantation to alleviate/eliminate allog ...

    Interleukin-2 (IL)-2 signaling plays a pivotal role in the activation of immune responses, and drugs that block this pathway have been shown to be effective for the immunosuppression in patients with organ transplantation to alleviate/eliminate allograft rejection. The first humanized monoclonal antibody (mAb) daclizumab falls into this category and shows high specificity and affinity against a key component of the IL-2 receptor complex, namely IL-2Rα. To reveal the molecular mechanism of the inhibition of the IL-2 signaling pathway by daclizumab, we determined the crystal structures of the daclizumab Fab in free form and in complex with the IL-2Rα ectodomain at 2.6 and 2.8 Å resolution, respectively. The daclizumab Fab adopts a similar conformation in the presence or absence of the IL-2Rα ectodomain. The antigen-binding site of daclizumab is mainly composed of five complementarity determining regions (CDRs) that form a large positively charged surface depression and two flanking patches that are generally hydrophobic. The conformational epitope consists of several discontinuous segments of the IL-2Rα ectodomain, a large portion of which overlaps with the regions that interact with IL-2, suggesting that the binding of daclizumab to IL-2Rα would prevent the IL-2 binding to IL-2Rα and the subsequent formation of the IL-2/IL-2Rαβγ(c) complex, and therefore block the IL-2 signaling pathway. These results also have implications for the design and development of improved mAb drugs targeting IL-2Rα.


    Organizational Affiliation

    State Key Laboratory of Molecular Biology and Research Center for Structural Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Heavy chain of Fab fragment of daclizumab
A, H
216N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Light chain of Fab fragment of daclizumab
B, L
212N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Interleukin-2 receptor subunit alpha
I, K
223Homo sapiensMutation(s): 0 
Gene Names: IL2RA
Find proteins for P01589 (Homo sapiens)
Go to Gene View: IL2RA
Go to UniProtKB:  P01589
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.86 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.253 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 102.167α = 90.00
b = 114.973β = 90.00
c = 247.555γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-09-15
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2013-10-16
    Type: Database references, Derived calculations