1BX7

HIRUSTASIN FROM HIRUDO MEDICINALIS AT 1.2 ANGSTROMS

• PDB DOI: https://doi.org/10.2210/pdb1BX7/pdb

• Classification: ANTI-COAGULANT
• Organism(s): Hirudo medicinalis
• Expression System: Saccharomyces cerevisiae
• Mutation(s): No 


• Deposited: 1998-10-14 Released: 1999-04-27 
• Deposition Author(s): Uson, I., Sheldrick, G.M., De La Fortelle, E., Bricogne, G., Di Marco, S., Priestle, J.P., Gruetter, M.G., Mittl, P.R.E.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.20 Å
• R-Value Free: 0.225 
• R-Value Observed: 0.179 

Literature

The 1.2 A crystal structure of hirustasin reveals the intrinsic flexibility of a family of highly disulphide-bridged inhibitors.

Uson, I., Sheldrick, G.M., de La Fortelle, E., Bricogne, G., Di Marco, S., Priestle, J.P., Grutter, M.G., Mittl, P.R.

(1999) Structure 7: 55-63

• PubMed: 10368273 
• DOI: https://doi.org/10.1016/s0969-2126(99)80009-4
• Primary Citation of Related Structures:  
  1BX7, 1BX8


• PubMed Abstract: 
  

  Leech-derived inhibitors have a prominent role in the development of new antithrombotic drugs, because some of them are able to block the blood coagulation cascade. Hirustasin, a serine protease inhibitor from the leech Hirudo medicinalis, binds specifically to tissue kallikrein and possesses structural similarity with antistasin, a potent factor Xa inhibitor from Haementeria officinalis. Although the 2.4 A structure of the hirustasin-kallikrein complex is known, classical methods such as molecular replacement were not successful in solving the structure of free hirustasin.

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Organizational Affiliation: 

Institut für Anorganische Chemie der Universität, Tammannstrasse 4, D-37077 Göttingen, Germany.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 6.08 kDa 
• Atom Count: 449 
• Modelled Residue Count: 51 
• Deposited Residue Count: 55 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
HIRUSTASIN	A	55	Hirudo medicinalis	Mutation(s): 0
UniProt
Find proteins for P80302 (Hirudo medicinalis) Explore P80302  Go to UniProtKB:  P80302

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
SO4	B [auth A], C [auth A]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.20 Å
• R-Value Free: 0.225 
• R-Value Observed: 0.179 
• Space Group: P 4₃ 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 37.713	α = 90
b = 37.713	β = 90
c = 67.812	γ = 90

Software Package:

Software Name	Purpose
MARXDS	data collection
MARSCALE	data reduction
SHELXL-97	model building
SHELXL-97	refinement
MARXDS	data reduction
MARSCALE	data scaling
SHELXL-97	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1999-04-27 
Deposition Author(s): Uson, I., Sheldrick, G.M., De La Fortelle, E., Bricogne, G., Di Marco, S., Priestle, J.P., Gruetter, M.G., Mittl, P.R.E.

Revision History  

• Version 1.0: 1999-04-27
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance