1H9I | pdb_00001h9i

COMPLEX OF EETI-II MUTANT WITH PORCINE TRYPSIN

• PDB DOI: https://doi.org/10.2210/pdb1H9I/pdb

• Classification: HYDROLASE/INHIBITOR
• Organism(s): Sus scrofa, Ecballium elaterium
• Mutation(s): Yes 


• Deposited: 2001-03-12 Released: 2004-07-26 
• Deposition Author(s): Kraetzner, R., Wentzel, A., Kolmar, H., Uson, I.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 
  0.175 (Depositor) 
• R-Value Work: 
  0.144 (DCC) 
• R-Value Observed: 
  0.142 (Depositor) 

Starting Model: experimental

Literature

Structure of Ecballium Elaterium Trypsin Inhibitor II (Eeti-II): A Rigid Molecular Scaffold

Kraetzner, R., Debreczeni, J.E., Pape, T., Schneider, T.R., Wentzel, A., Kolmar, H., Sheldrick, G.M., Uson, I.

(2005) Acta Crystallogr D Biol Crystallogr 61: 1255

• PubMed: 16131759 
• DOI: https://doi.org/10.1107/S0907444905021207
• Primary Citation Related Structures: 
  1H9H, 1H9I, 1W7Z


• PubMed Abstract: 
  

  The Ecballium elaterium trypsin inhibitor II (EETI-II) belongs to the family of squash inhibitors and is one of the strongest inhibitors known for trypsin. The eight independent molecules of EETI-II in the crystal structure reported here provide a good opportunity to test the hypothesis that this small cystine-knot protein (knottin) is sufficiently rigid to be used as a molecular scaffold for protein-engineering purposes. To extend this test, the structures of two complexes of EETI-II with trypsin have also been determined, one carrying a four-amino-acid mutation of EETI-II. The remarkable similarity of these structures confirms the rigidity of the molecular framework and hence its suitability as a molecular scaffold.

---

Organizational Affiliation: 
• Lehrstuhl für Strukturchemie, Georg-August-Universität Göttingen, Tammannstrasse 4, D37077 Göttingen, Germany.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors and generated by PQS (software)

Macromolecule Content 

• Total Structure Weight: 27.57 kDa 
• Atom Count: 2,019 
• Modeled Residue Count: 253 
• Deposited Residue Count: 259 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
TRYPSIN	A [auth E]	223	Sus scrofa	Mutation(s): 0  EC: 3.4.21.4
UniProt
Find proteins for P00761 (Sus scrofa) Explore P00761  Go to UniProtKB:  P00761

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
TRYPSIN INHIBITOR II	B [auth I]	36	Ecballium elaterium	Mutation(s): 4
UniProt
Find proteins for P12071 (Ecballium elaterium) Explore P12071  Go to UniProtKB:  P12071

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
CA	C [auth E]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free:  0.175 (Depositor) 
• R-Value Work:  0.144 (DCC) 
• R-Value Observed: 0.142 (Depositor) 

Space Group: I 4

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 139.862	α = 90
b = 139.862	β = 90
c = 33.667	γ = 90

Software Package:

Software Name	Purpose
SHELXL-97	refinement
DENZO	data reduction
SCALEPACK	data scaling
EPMR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2004-07-26 
Deposition Author(s): Kraetzner, R., Wentzel, A., Kolmar, H., Uson, I.

Revision History  

• Version 1.0: 2004-07-26
  Type: Initial release
  
• Version 1.1: 2011-05-07
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2018-04-04
  Changes: Data collection
• Version 1.4: 2019-05-22
  Changes: Data collection, Refinement description
• Version 1.5: 2023-12-13
  Changes: Data collection, Database references, Derived calculations, Other, Refinement description
• Version 1.6: 2024-10-16
  Changes: Structure summary