3HI5

Crystal structure of Fab fragment of AL-57


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.234 
  • R-Value Observed: 0.236 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural basis of activation-dependent binding of ligand-mimetic antibody AL-57 to integrin LFA-1.

Zhang, H.Liu, J.H.Yang, W.Springer, T.Shimaoka, M.Wang, J.H.

(2009) Proc Natl Acad Sci U S A 106: 18345-18350

  • DOI: 10.1073/pnas.0909301106
  • Primary Citation of Related Structures:  
    3HI5, 3HI6

  • PubMed Abstract: 
  • The activity of integrin LFA-1 (alpha(L)beta(2)) to its ligand ICAM-1 is regulated through the conformational changes of its ligand-binding domain, the I domain of alpha(L) chain, from an inactive, low-affinity closed form (LA), to an intermediate-af ...

    The activity of integrin LFA-1 (alpha(L)beta(2)) to its ligand ICAM-1 is regulated through the conformational changes of its ligand-binding domain, the I domain of alpha(L) chain, from an inactive, low-affinity closed form (LA), to an intermediate-affinity form (IA), and then finally, to a high-affinity open form (HA). A ligand-mimetic human monoclonal antibody AL-57 (activated LFA-1 clone 57) was identified by phage display to specifically recognize the affinity-upregulated I domain. Here, we describe the crystal structures of the Fab fragment of AL-57 in complex with IA, as well as in its unligated form. We discuss the structural features conferring AL-57's strong selectivity for the high affinity, open conformation of the I domain. The AL-57-binding site overlaps the ICAM-1 binding site on the I domain. Furthermore, an antibody Asp mimics an ICAM Glu by forming a coordination to the metal-ion dependent adhesion site (MIDAS). The structure also reveals better shape complementarity and a more hydrophobic interacting interface in AL-57 binding than in ICAM-1 binding. The results explain AL-57's antagonistic mimicry of LFA-1's natural ligands, the ICAM molecules.


    Organizational Affiliation

    Department of Pediatrics, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Heavy chain of Fab fragment of AL-57 against alpha L I domainH220Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
light chain of Fab fragment of AL-57 against alpha L I domainL212Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.234 
  • R-Value Observed: 0.236 
  • Space Group: P 61 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 84.74α = 90
b = 84.74β = 90
c = 317.17γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
ADSCdata collection

Structure Validation

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Entry History 

Deposition Data

  • Deposited Date: 2009-05-18 
  • Released Date: 2009-09-22 
  • Deposition Author(s): Zhang, H., Wang, J.

Revision History 

  • Version 1.0: 2009-09-22
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.2: 2017-11-01
    Changes: Refinement description