3QK1

Crystal Structure of Enterokinase-like Trypsin Variant

• PDB DOI: https://doi.org/10.2210/pdb3QK1/pdb

• Classification: HYDROLASE
• Organism(s): Bos taurus
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2011-01-31 Released: 2011-03-23 
• Deposition Author(s): Schoepfel, M., Tziridis, A., Arnold, U., Stubbs, M.T.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.08 Å
• R-Value Free: 0.237 
• R-Value Work: 0.182 
• R-Value Observed: 0.188 

Starting Model: experimental

Literature

Towards a restriction proteinase: construction of a self-activating enzyme.

Schopfel, M., Tziridis, A., Arnold, U., Stubbs, M.T.

(2011) Chembiochem 12: 1523-1527

• PubMed: 21387509 
• DOI: https://doi.org/10.1002/cbic.201000787
• Primary Citation of Related Structures:  
  3QK1

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Organizational Affiliation: 

Institut für Biochemie und Biotechnologie, Martin-Luther Universität Halle-Wittenberg, Halle, Germany.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

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

Macromolecule Content

• Total Structure Weight: 25.17 kDa 
• Atom Count: 1,833 
• Modelled Residue Count: 224 
• Deposited Residue Count: 229 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Cationic trypsin	A	229	Bos taurus	Mutation(s): 4  EC: 3.4.21.4
UniProt
Find proteins for P00760 (Bos taurus) Explore P00760  Go to UniProtKB:  P00760

Small Molecules

Ligands 6 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
BEN	L [auth A]	BENZAMIDINE C7 H8 N2 PXXJHWLDUBFPOL-UHFFFAOYSA-N
SO4	C [auth A], D [auth A], E [auth A]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L
GOL	K [auth A]	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N
IMD	I [auth A]	IMIDAZOLE C3 H5 N2 RAXXELZNTBOGNW-UHFFFAOYSA-O
EDO	F [auth A], G [auth A], H [auth A], J [auth A]	1,2-ETHANEDIOL C2 H6 O2 LYCAIKOWRPUZTN-UHFFFAOYSA-N
CA	B [auth A]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.08 Å
• R-Value Free: 0.237 
• R-Value Work: 0.182 
• R-Value Observed: 0.188 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 60.71	α = 90
b = 63.76	β = 90
c = 69.69	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
PDB_EXTRACT	data extraction
HKL-2000	data reduction
HKL-2000	data scaling
AMoRE	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2011-03-23 
Deposition Author(s): Schoepfel, M., Tziridis, A., Arnold, U., Stubbs, M.T.

Revision History  

• Version 1.0: 2011-03-23
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Version format compliance
• Version 1.2: 2011-07-20
  Changes: Database references
• Version 1.3: 2023-09-13
  Changes: Data collection, Database references, Derived calculations, Refinement description
• Version 1.4: 2024-10-09
  Changes: Structure summary