2AFQ

1.9 angstrom crystal structure of wild-type human thrombin in the sodium free state


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.198 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Crystal structure of wild-type human thrombin in the Na+-free state

Johnson, D.J.D.Adams, T.E.Li, W.Huntington, J.A.

(2005) Biochem J 392: 21-28

  • DOI: 10.1042/BJ20051217
  • Primary Citation of Related Structures:  
    2AFQ

  • PubMed Abstract: 
  • Regulation of thrombin activity is critical for haemostasis and the prevention of thrombosis. Thrombin has several procoagulant substrates, including fibrinogen and platelet receptors, and essential cofactors for stimulating its own formation. Howeve ...

    Regulation of thrombin activity is critical for haemostasis and the prevention of thrombosis. Thrombin has several procoagulant substrates, including fibrinogen and platelet receptors, and essential cofactors for stimulating its own formation. However, thrombin is also capable of serving an anticoagulant function by activating protein C. The specificity of thrombin is primarily regulated by binding to the cofactor TM (thrombomodulin), but co-ordination of Na+ can also affect thrombin activity. The Na+-free form is often referred to as 'slow' because of reduced rates of cleavage of procoagulant substrates, but the slow form is still capable of rapid activation of protein C in the presence of TM. The molecular basis of the slow proteolytic activity of thrombin has remained elusive, in spite of two decades of solution studies and many published crystallographic structures. In the present paper, we report the first structure of wild-type unliganded human thrombin grown in the absence of co-ordinating Na+. The Na+-binding site is observed in a highly ordered position 6 A (1 A=0.1 nm) removed from that seen in the Na+-bound state. The movement of the Na+ loop results in non-catalytic hydrogen-bonding in the active site and blocking of the S1 and S2 substrate-binding pockets. Similar, if more dramatic, changes were observed in a previous structure of the constitutively slow thrombin variant E217K. The slow behaviour of thrombin in solutions devoid of Na+ can now be understood in terms of an equilibrium between an inert species, represented by the crystal structure described in the present paper, and an active form, where the addition of Na+ populates the active state.


    Organizational Affiliation

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



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ProthrombinAC29Homo sapiensMutation(s): 0 
Gene Names: F2
EC: 3.4.21.5
Find proteins for P00734 (Homo sapiens)
Explore P00734 
Go to UniProtKB:  P00734
NIH Common Fund Data Resources
PHAROS  P00734
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
ProthrombinBD259Homo sapiensMutation(s): 0 
Gene Names: F2
EC: 3.4.21.5
Find proteins for P00734 (Homo sapiens)
Explore P00734 
Go to UniProtKB:  P00734
NIH Common Fund Data Resources
PHAROS  P00734
Protein Feature View
Expand
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download CCD File 
B, D
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.198 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 153.34α = 90
b = 82.31β = 90
c = 50.93γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
MOLREPphasing
ARP/wARPmodel building
CNSrefinement
CCP4data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-11-15
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 1.3: 2011-11-16
    Changes: Atomic model
  • Version 1.4: 2016-12-14
    Changes: Structure summary