1BA7

SOYBEAN TRYPSIN INHIBITOR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.160 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structure of the Kunitz-type soybean trypsin inhibitor (STI): implication for the interactions between members of the STI family and tissue-plasminogen activator.

De Meester, P.Brick, P.Lloyd, L.F.Blow, D.M.Onesti, S.

(1998) Acta Crystallogr.,Sect.D 54: 589-597


  • PubMed Abstract: 
  • The Kunitz-type soybean trypsin inhibitor (STI) has played a key role in the early study of proteinases, having been used as the main substrate in the biochemical and kinetic work that led to the definition of the standard mechanism of action of prot ...

    The Kunitz-type soybean trypsin inhibitor (STI) has played a key role in the early study of proteinases, having been used as the main substrate in the biochemical and kinetic work that led to the definition of the standard mechanism of action of proteinase inhibitors. A partial structure of STI complexed with porcine trypsin has previously been reported, in which the first 93 residues of the inhibitor, including the region of contact with trypsin, were relatively well defined, whereas for the remaining part of the peptide chain only some Calpha atoms were located. The structure of the inhibitor in its free form has now been determined by molecular replacement to 2.5 A, using the coordinates of the homologous Erythrina trypsin inhibitor as a search model. When the refined atomic coordinates of STI are compared with the partial model previously available, the conformation of the reactive-site loop and its position with respect to the main body of the molecule does not change when the inhibitor interacts with trypsin. There are instead, despite the high similarity in the overall tertiary structure, significant differences between STI and Erythrina trypsin inhibitor (ETI) in the region which is in contact with the enzyme in the STI:trypsin crystal structure. Some of these differences can explain the unique specificity of ETI and its ability to inhibit the fibrinolytic enzyme tissue-type plasminogen activator.


    Related Citations: 
    • Crystal Structure of a Kunitz-Type Trypsin Inhibitor from Erythrina Caffra Seeds
      Onesti, S.,Brick, P.,Blow, D.M.
      (1991) J.Mol.Biol. 217: 153
    • Crystal Structure of the Complex of Porcine Trypsin with Soybean Trypsin Inhibitor (Kunitz) at 2.6-A Resolution
      Sweet, R.M.,Wright, H.T.,Janin, J.,Chothia, C.H.,Blow, D.M.
      (1974) Biochemistry 13: 4212


    Organizational Affiliation

    Blackett Laboratory, Imperial College, London SW7 2BZ, England.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
TRYPSIN INHIBITOR (KUNITZ)
A, B
181Glycine maxGene Names: KTI3
Find proteins for P01070 (Glycine max)
Go to UniProtKB:  P01070
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.160 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 39.110α = 71.75
b = 53.870β = 90.00
c = 58.200γ = 82.98
Software Package:
Software NamePurpose
CCP4data reduction
CCP4data scaling
MADNESdata reduction
MADNESdata collection
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-06-17
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2018-04-18
    Type: Data collection, Other