4ZOT

Crystal structure of BbKI, a disulfide-free plasma kallikrein inhibitor at 1.4 A resolution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.167 
  • R-Value Work: 0.123 
  • R-Value Observed: 0.125 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Structure of BbKI, a disulfide-free plasma kallikrein inhibitor.

Zhou, D.Hansen, D.Shabalin, I.G.Gustchina, A.Vieira, D.F.de Brito, M.V.Araujo, A.P.Oliva, M.L.Wlodawer, A.

(2015) Acta Crystallogr F Struct Biol Commun 71: 1055-1062

  • DOI: https://doi.org/10.1107/S2053230X15011127
  • Primary Citation of Related Structures:  
    4ZOT

  • PubMed Abstract: 

    A serine protease inhibitor from Bauhinia bauhinioides (BbKI) belongs to the Kunitz family of plant inhibitors, which are common in plant seeds. BbKI does not contain any disulfides, unlike most other members of this family. It is a potent inhibitor of plasma kallikrein, in addition to other serine proteases, and thus exhibits antithrombotic activity. A high-resolution crystal structure of recombinantly expressed BbKI was determined (at 1.4 Å resolution) and was compared with the structures of other members of the family. Modeling of a complex of BbKI with plasma kallikrein indicates that changes in the local structure of the reactive loop that includes the specificity-determining Arg64 are necessary in order to explain the tight binding. An R64A mutant of BbKI was found to be a weaker inhibitor of plasma kallikrein, but was much more potent against plasmin, suggesting that this mutant may be useful for preventing the breakup of fibrin and maintaining clot stability, thus preventing excessive bleeding.


  • Organizational Affiliation

    Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Kunitz-type serine protease inhibitor BbKI168Bauhinia bauhinioidesMutation(s): 0 
UniProt
Find proteins for P83052 (Bauhinia bauhinioides)
Explore P83052 
Go to UniProtKB:  P83052
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP83052
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.167 
  • R-Value Work: 0.123 
  • R-Value Observed: 0.125 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 46.736α = 90
b = 59.462β = 90
c = 64.011γ = 90
Software Package:
Software NamePurpose
SERGUIdata collection
HKL-3000data reduction
HKL-3000data scaling
PHASERphasing
Cootmodel building
REFMACrefinement
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Cancer Institute (NIH/NCI)United States--

Revision History  (Full details and data files)

  • Version 1.0: 2015-05-20
    Type: Initial release
  • Version 1.1: 2015-08-12
    Changes: Database references
  • Version 1.2: 2015-08-19
    Changes: Database references
  • Version 1.3: 2019-12-04
    Changes: Author supporting evidence, Derived calculations
  • Version 1.4: 2023-09-27
    Changes: Data collection, Database references, Refinement description