1OYH

Crystal Structure of P13 Alanine Variant of Antithrombin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.62 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.221 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

The influence of hinge region residue Glu-381 on antithrombin allostery and metastability

Johnson, D.J.D.Huntington, J.A.

(2004) J.Biol.Chem. 279: 4913-4921

  • DOI: 10.1074/jbc.M311644200

  • PubMed Abstract: 
  • Antithrombin becomes an efficient inhibitor of factor Xa and thrombin by binding a specific pentasaccharide sequence found on a small fraction of the heparan sulfate proteoglycans lining the microvaculature. In the structure of native antithrombin, t ...

    Antithrombin becomes an efficient inhibitor of factor Xa and thrombin by binding a specific pentasaccharide sequence found on a small fraction of the heparan sulfate proteoglycans lining the microvaculature. In the structure of native antithrombin, the reactive center loop is restrained due to the insertion of its hinge region into the main beta-sheet A, whereas in the heparin-activated state the reactive center loop is freed from beta-sheet A. In both structures, hinge region residue Glu-381 makes several stabilizing contacts. To determine the role of these contacts in the allosteric mechanism of antithrombin activation, we replaced Glu-381 with an alanine. This variant is less active toward its target proteases than control antithrombin, due to a perturbation of the equilibrium between the two forms, and to an increase in stoichiometry of inhibition. Pentasaccharide binding affinity is reduced 4-fold due to an increase in the off-rate. These data suggest that the main role of Glu-381 is to stabilize the activated conformation. Stability studies also showed that the E381A variant is resistant to continued insertion of its reactive center loop upon incubation at 50 degrees C, suggesting new stabilizing interactions in the native structure. To test this hypothesis, and to aid in the interpretation of the kinetic data we solved to 2.6 A the structure of the variant. We conclude that wild-type Glu-381 interactions stabilize the activated state and decreases the energy barrier to full loop insertion.


    Organizational Affiliation

    University of Cambridge, Department of Haematology, Cambridge Institute for Medical Research, Division of Structural Medicine, Thrombosis Research Unit, Wellcome Trust MRC Building, Hills Road, Cambridge CB2 2XY, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Antithrombin-III
I
432Homo sapiensGene Names: SERPINC1 (AT3)
Find proteins for P01008 (Homo sapiens)
Go to Gene View: SERPINC1
Go to UniProtKB:  P01008
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Antithrombin-III
L
432Homo sapiensGene Names: SERPINC1 (AT3)
Find proteins for P01008 (Homo sapiens)
Go to Gene View: SERPINC1
Go to UniProtKB:  P01008
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MAN
Query on MAN

Download SDF File 
Download CCD File 
L
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
BMA
Query on BMA

Download SDF File 
Download CCD File 
L
BETA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-RWOPYEJCSA-N
 Ligand Interaction
NDG
Query on NDG

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Download CCD File 
L
2-(ACETYLAMINO)-2-DEOXY-A-D-GLUCOPYRANOSE
C8 H15 N O6
OVRNDRQMDRJTHS-PVFLNQBWSA-N
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
I, L
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.62 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.221 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 68.998α = 90.00
b = 98.573β = 105.53
c = 89.350γ = 90.00
Software Package:
Software NamePurpose
MAR345data collection
MOLREPphasing
SCALAdata scaling
CCP4data scaling
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-04-13
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance
  • Version 1.3: 2017-10-11
    Type: Refinement description