1TOC

STRUCTURE OF SERINE PROTEINASE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.10 Å
  • R-Value Work: 0.230 
  • R-Value Observed: 0.230 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

The ornithodorin-thrombin crystal structure, a key to the TAP enigma?

van de Locht, A.Stubbs, M.T.Bode, W.Friedrich, T.Bollschweiler, C.Hoffken, W.Huber, R.

(1996) EMBO J 15: 6011-6017

  • Primary Citation of Related Structures:  
    1TOC

  • PubMed Abstract: 

    Ornithodorin, isolated from the blood sucking soft tick Ornithodoros moubata, is a potent (Ki = 10(-12) M) and highly selective thrombin inhibitor. Internal sequence homology indicates a two domain protein. Each domain resembles the Kunitz inhibitor basic pancreatic trypsin inhibitor (BPTI) and also the tick anticoagulant peptide (TAP) isolated from the same organism. The 3.1 A crystal structure of the ornithodorin-thrombin complex confirms that both domains of ornithodorin exhibit a distorted BPTI-like fold. The N-terminal portion and the C-terminal helix of each domain are structurally very similar to BPTI, whereas the regions corresponding to the binding loop of BPTI adopt different conformations. Neither of the two 'reactive site loops' of ornithodorin contacts the protease in the ornithodorin-thrombin complex. Instead, the N-terminal residues of ornithodorin bind to the active site of thrombin, reminiscent of the thrombin-hirudin interaction. The C-terminal domain binds at the fibrinogen recognition exosite. Molecular recognition of its target protease by this double-headed Kunitz-type inhibitor diverges considerably from other members of this intensely studied superfamily. The complex structure provides a model to explain the perplexing results of mutagenesis studies on the TAP-factor Xa interaction.


  • Organizational Affiliation

    Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Martinsreid, Germany.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
THROMBINA,
D [auth C],
G [auth E],
J [auth G]
49Bos taurusMutation(s): 0 
EC: 3.4.21.5
UniProt
Find proteins for P00735 (Bos taurus)
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Go to UniProtKB:  P00735
Entity Groups  
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UniProt GroupP00735
Sequence Annotations
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
THROMBINB,
E [auth D],
H [auth F],
K [auth H]
259Bos taurusMutation(s): 0 
EC: 3.4.21.5
UniProt
Find proteins for P00735 (Bos taurus)
Explore P00735 
Go to UniProtKB:  P00735
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UniProt GroupP00735
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  • Reference Sequence
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
ORNITHODORINC [auth R],
F [auth S],
I [auth T],
L [auth U]
120Ornithodoros moubataMutation(s): 0 
UniProt
Find proteins for P56409 (Ornithodoros moubata)
Explore P56409 
Go to UniProtKB:  P56409
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP56409
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.10 Å
  • R-Value Work: 0.230 
  • R-Value Observed: 0.230 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 125.3α = 90
b = 89.9β = 108.4
c = 101.4γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1997-07-23
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-10-30
    Changes: Data collection, Database references, Structure summary