2STA

ANIONIC SALMON TRYPSIN IN COMPLEX WITH SQUASH SEED INHIBITOR (CUCURBITA MAXIMA TRYPSIN INHIBITOR I)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.193 

wwPDB Validation 3D Report Full Report


This is version 1.2 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.,Sect.D 55: 139-148

  • DOI: 10.1107/S090744499801052X
  • Primary Citation of Related Structures:  

  • 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 ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (TRYPSIN)
E
222Salmo salarMutation(s): 0 
EC: 3.4.21.4
Find proteins for P35031 (Salmo salar)
Go to UniProtKB:  P35031
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (TRYPSIN INHIBITOR)
I
29Cucurbita maximaMutation(s): 0 
Find proteins for P01074 (Cucurbita maxima)
Go to UniProtKB:  P01074
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
E
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.193 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 62.300α = 90.00
b = 63.700β = 90.00
c = 82.300γ = 90.00
Software Package:
Software NamePurpose
CCP4data scaling
X-PLORrefinement
DENZOdata reduction
X-PLORphasing
CCP4data reduction
X-PLORmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-01-19
    Type: Initial release
  • Version 1.1: 2008-04-26
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance