1GCT

IS GAMMA-CHYMOTRYPSIN A TETRAPEPTIDE ACYL-ENZYME ADDUCT OF GAMMA-CHYMOTRYPSIN?

• PDB DOI: https://doi.org/10.2210/pdb1GCT/pdb

• Classification: HYDROLASE/PEPTIDE
• Organism(s): Bos taurus
• Mutation(s): No 


• Deposited: 1990-09-04 Released: 1991-10-15 
• Deposition Author(s): Dixon, M.M., Matthews, B.W.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.60 Å
• R-Value Work: 0.173 

Literature

Is gamma-chymotrypsin a tetrapeptide acyl-enzyme adduct of alpha-chymotrypsin?

Dixon, M.M., Matthews, B.W.

(1989) Biochemistry 28: 7033-7038

• PubMed: 2819046 
• DOI: https://doi.org/10.1021/bi00443a038
• Primary Citation of Related Structures:  
  1GCT


• PubMed Abstract: 
  

  Refinement of the structure of gamma-chymotrypsin based on X-ray crystallographic data to 1.6-A resolution has confirmed the overall conformation of the molecule as reported previously [Cohen, G. H., Silverton, E. W., & Davies, D. R. (1981) J. Mol. Biol. 148, 449-479]. In addition, the new refinement suggests that gamma-chymotrypsin, which is operationally defined by its crystalline habit, may not be the free enzyme but rather a complex, possibly an acyl-enzyme adduct, with the tetrapeptide Pro-Gly-Ala-Tyr (or a close homologue). The crystallographic refinement provides a detailed geometrical description of the enzyme-substrate-solvent interactions that occur in the presumptive adduct.

---

Organizational Affiliation: 

Institute of Molecular Biology, University of Oregon, Eugene 97403.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Hetero 8-mer - A2B2C2D2 Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Hetero 8-mer - A2B2C1D1E1F1 

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

Macromolecule Content

• Total Structure Weight: 25.85 kDa 
• Atom Count: 1,935 
• Modelled Residue Count: 242 
• Deposited Residue Count: 246 
• Unique protein chains: 4

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
GAMMA-CHYMOTRYPSIN A	A	13	Bos taurus	Mutation(s): 0  EC: 3.4.21.1
UniProt
Find proteins for P00766 (Bos taurus) Explore P00766  Go to UniProtKB:  P00766

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
GAMMA-CHYMOTRYPSIN A	B	131	Bos taurus	Mutation(s): 0  EC: 3.4.21.1
UniProt
Find proteins for P00766 (Bos taurus) Explore P00766  Go to UniProtKB:  P00766

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
GAMMA-CHYMOTRYPSIN A	C	97	Bos taurus	Mutation(s): 0  EC: 3.4.21.1
UniProt
Find proteins for P00766 (Bos taurus) Explore P00766  Go to UniProtKB:  P00766

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
TETRAPEPTIDE ADDUCT	D	5	N/A	Mutation(s): 0

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
SO4	E [auth B]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.60 Å
• R-Value Work: 0.173 
• Space Group: P 4₂ 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 69.8	α = 90
b = 69.8	β = 90
c = 98.1	γ = 90

Software Package:

Software Name	Purpose
TNT	refinement
OSCTST	data reduction
AGROVATA/ROTAVATE	data scaling

Structure Validation

Entry History 

Deposition Data

• Released Date: 1991-10-15 
Deposition Author(s): Dixon, M.M., Matthews, B.W.

Revision History  

• Version 1.0: 1991-10-15
  Type: Initial release
  
• Version 1.1: 2008-03-06
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Derived calculations, Version format compliance
• Version 1.3: 2012-12-12
  Changes: Other
• Version 1.4: 2013-03-13
  Changes: Other
• Version 1.5: 2024-06-05
  Changes: Data collection, Database references, Derived calculations, Other
• Version 1.6: 2024-10-30
  Changes: Structure summary