1AKS

CRYSTAL STRUCTURE OF THE FIRST ACTIVE AUTOLYSATE FORM OF THE PORCINE ALPHA TRYPSIN

• PDB DOI: https://doi.org/10.2210/pdb1AKS/pdb

• Classification: SERINE PROTEASE
• Organism(s): Sus scrofa
• Mutation(s): No 


• Deposited: 1996-07-24 Released: 1997-02-12 
• Deposition Author(s): Johnson, A., Krishnaswamy, S., Sundaram, P.V., Pattabhi, V.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Work: 0.200 
• R-Value Observed: 0.200 

Literature

The first structure at 1.8 A resolution of an active autolysate form of porcine alpha-trysoin.

Johnson, A., Krishnaswamy, S., Sundaram, P.V., Pattabhi, V.

(1997) Acta Crystallogr D Biol Crystallogr 53: 311-315

• PubMed: 15299934 
• DOI: https://doi.org/10.1107/S0907444997000358
• Primary Citation of Related Structures:  
  1AKS


• PubMed Abstract: 
  

  The first crystal structure of an active autolysate form of porcine alpha-trypsin (APT), a two-chain molecule obtained from the limited autolysis of porcine beta-trypsin at position Lys145-Ser146, has been determined. APT crystallizes in space group P2(1)2(1)2(1) with one protein molecule in the asymmetric unit. The structure was solved by molecular replacement followed by refinement using X-PLOR to an R factor of 0.200 and an R(free) of 0.285 for 8.0-1.8 A data with r.m.s deviations from ideal values of 0.01 A and 1.7 degrees for bond lengths and bond angles, respectively. Comparison with inactive autolysate porcine epsilon-trypsin (EPT) and porcine beta-trypsin in complex with bittergourd trypsin inhibitor (MCT) revealed a small but systematic directional chain shift around the active-site residues from APT to EPT to MCT.

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Organizational Affiliation: 

Department of Crystallography and Biophysics, University of Madras, India.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

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

Macromolecule Content

• Total Structure Weight: 23.55 kDa 
• Atom Count: 1,755 
• Modelled Residue Count: 223 
• Deposited Residue Count: 223 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
ALPHA TRYPSIN	A	125	Sus scrofa	Mutation(s): 0  EC: 3.4.21.4
UniProt
Find proteins for P00761 (Sus scrofa) Explore P00761  Go to UniProtKB:  P00761

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
ALPHA TRYPSIN	B	98	Sus scrofa	Mutation(s): 0  EC: 3.4.21.4
UniProt
Find proteins for P00761 (Sus scrofa) Explore P00761  Go to UniProtKB:  P00761

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
CA	C [auth A]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Work: 0.200 
• R-Value Observed: 0.200 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 77.7	α = 90
b = 53.82	β = 90
c = 47.08	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	refinement

Structure Validation

Entry History 

Deposition Data

• Released Date: 1997-02-12 
Deposition Author(s): Johnson, A., Krishnaswamy, S., Sundaram, P.V., Pattabhi, V.

Revision History  

• Version 1.0: 1997-02-12
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2024-06-05
  Changes: Data collection, Database references, Derived calculations, Other
• Version 1.4: 2024-10-23
  Changes: Structure summary