Experimental Data Snapshot

  • Resolution: 1.25 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.166 
  • R-Value Observed: 0.166 

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This is version 1.3 of the entry. See complete history


Engineered allosteric mutants of the integrin alphaMbeta2 I domain: structural and functional studies

McCleverty, C.J.Liddington, R.C.

(2003) Biochem J 372: 121-127

  • DOI: https://doi.org/10.1042/BJ20021273
  • Primary Citation of Related Structures:  
    1MF7, 1N9Z, 1NA5

  • PubMed Abstract: 

    The alpha-I domain, found in the alpha-subunit of the leucocyte integrins such as alphaMbeta2 and alphaLbeta2, switches between the open and closed tertiary conformations, reflecting the high- and low-affinity ligand-binding states of the integrin that are required for regulated cell adhesion and migration. In the present study we show, by using point mutations and engineered disulphide bonds, that ligand affinity can be reduced or increased allosterically by altering the equilibrium between the closed and open states. We determined equilibrium constants for the binding of two ligands, fibrinogen and intercellular cell-adhesion molecule 1, to the alphaM-I domain by surface plasmon resonance, and determined crystal structures of a low-affinity mutant. Locking the domain in the open conformation increases affinity by a factor of no greater than 10, consistent with a closely balanced equilibrium between the two conformations in the absence of ligand. This behaviour contrasts with that of the unliganded alphaL-I domain, for which the equilibrium lies strongly in favour of the closed conformation. These results suggest significant differences in the way the parent integrins regulate I domain conformation and hence ligand affinity.

  • Organizational Affiliation

    The Burnham Institute, 10901 North Torrey Pines Rd, La Jolla, CA 92037, U.S.A.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
INTEGRIN ALPHA M194Homo sapiensMutation(s): 1 
Gene Names: ITGAMCD11BCR3A
UniProt & NIH Common Fund Data Resources
Find proteins for P11215 (Homo sapiens)
Explore P11215 
Go to UniProtKB:  P11215
PHAROS:  P11215
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP11215
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.25 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.166 
  • R-Value Observed: 0.166 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 38.64α = 90
b = 51.03β = 90
c = 102.38γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-05-20
    Type: Initial release
  • Version 1.1: 2008-04-28
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2021-10-27
    Changes: Database references