2BTC

BOVINE TRYPSIN IN COMPLEX WITH SQUASH SEED INHIBITOR (CUCURBITA PEPO TRYPSIN INHIBITOR II)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.183 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

High-resolution structures of three new trypsin-squash-inhibitor complexes: a detailed comparison with other trypsins and their complexes.

Helland, R.Berglund, G.I.Otlewski, J.Apostoluk, W.Andersen, O.A.Willassen, N.P.Smalas, A.O.

(1999) Acta Crystallogr D Biol Crystallogr 55: 139-148

  • DOI: https://doi.org/10.1107/S090744499801052X
  • Primary Citation of Related Structures:  
    2BTC, 2STA, 2STB

  • PubMed Abstract: 

    An anionic trypsin from Atlantic salmon and bovine trypsin have been complexed with the squash-seed inhibitors, CMTI-I (Cucurbita maxima trypsin inhibitor I, P1 Arg) and CPTI-II (Cucurbita pepo trypsin inhibitor II, P1 Lys). The crystal structures of three such complexes have been determined to 1.5-1.8 A resolution and refined to crystallographic R factors ranging from 17.6 to 19.3%. The two anionic salmon-trypsin complexes (ST-CPTI and ST-CMTI) and the bovine-trypsin complex (BT-CPTI) have been compared to other trypsin-inhibitor complexes by means of general structure and primary and secondary binding features. In all three new structures, the primary binding residue of the inhibitor binds to trypsin in the classical manner, but with small differences in the primary and secondary binding patterns. Lysine in CPTI-II binds deeper in the specificity pocket of bovine trypsin than lysine in other known lysine-bovine-trypsin complexes, and anionic salmon trypsin lacks some of the secondary binding interactions found in the complexes formed between squash inhibitors and bovine trypsin. The ST-CMTI complex was formed from the reactive-site-cleaved form of the inhibitor. However, well defined electron density was observed for the P1-P1' peptide bond, together with a hydrogen-bonding pattern virtually identical to those of all serine-protease-protein-inhibitor complexes, indicating a resynthesis of the scissile bond.


  • Organizational Affiliation

    Department of Chemistry, University of Tromso, N-9037 Tromso, Norway.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
PROTEIN (TRYPSIN)A [auth E]223Bos taurusMutation(s): 0 
EC: 3.4.21.4
UniProt
Find proteins for P00760 (Bos taurus)
Explore P00760 
Go to UniProtKB:  P00760
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00760
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
PROTEIN (TRYPSIN INHIBITOR)B [auth I]29Cucurbita pepoMutation(s): 0 
UniProt
Find proteins for P10293 (Cucurbita pepo)
Explore P10293 
Go to UniProtKB:  P10293
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP10293
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download Ideal Coordinates CCD File 
C [auth E]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.183 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 59.1α = 90
b = 55.7β = 90
c = 74.9γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
CCP4data reduction
X-PLORmodel building
X-PLORrefinement
CCP4data scaling
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2000-01-19
    Type: Initial release
  • Version 1.1: 2008-04-26
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-23
    Changes: Data collection, Database references, Derived calculations, Refinement description