1AZX

ANTITHROMBIN/PENTASACCHARIDE COMPLEX


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.195 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The anticoagulant activation of antithrombin by heparin.

Jin, L.Abrahams, J.P.Skinner, R.Petitou, M.Pike, R.N.Carrell, R.W.

(1997) Proc.Natl.Acad.Sci.USA 94: 14683-14688


  • PubMed Abstract: 
  • Antithrombin, a plasma serpin, is relatively inactive as an inhibitor of the coagulation proteases until it binds to the heparan side chains that line the microvasculature. The binding specifically occurs to a core pentasaccharide present both in the ...

    Antithrombin, a plasma serpin, is relatively inactive as an inhibitor of the coagulation proteases until it binds to the heparan side chains that line the microvasculature. The binding specifically occurs to a core pentasaccharide present both in the heparans and in their therapeutic derivative heparin. The accompanying conformational change of antithrombin is revealed in a 2.9-A structure of a dimer of latent and active antithrombins, each in complex with the high-affinity pentasaccharide. Inhibitory activation results from a shift in the main sheet of the molecule from a partially six-stranded to a five-stranded form, with extrusion of the reactive center loop to give a more exposed orientation. There is a tilting and elongation of helix D with the formation of a 2-turn helix P between the C and D helices. Concomitant conformational changes at the heparin binding site explain both the initial tight binding of antithrombin to the heparans and the subsequent release of the antithrombin-protease complex into the circulation. The pentasaccharide binds by hydrogen bonding of its sulfates and carboxylates to Arg-129 and Lys-125 in the D-helix, to Arg-46 and Arg-47 in the A-helix, to Lys-114 and Glu-113 in the P-helix, and to Lys-11 and Arg-13 in a cleft formed by the amino terminus. This clear definition of the binding site will provide a structural basis for developing heparin analogues that are more specific toward their intended target antithrombin and therefore less likely to exhibit side effects.


    Organizational Affiliation

    Department of Haematology, University of Cambridge, Hills Road, Cambridge CB2 2QH, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

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

Download SDF File 
Download CCD File 
I, L
HEPARIN PENTASACCHARIDE
C36 H60 O55 S9
MQLWHPBUPXUQHM-XAYBSJBFSA-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
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
NTPKd: 0.4 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.195 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 70.440α = 90.00
b = 86.970β = 108.88
c = 97.220γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
CCP4data scaling
MOSFLMdata reduction
CCP4data reduction
TNTrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-01-13
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance