Biological Assembly 1  

 3D View: Structure | Ligand Interaction

Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Hetero 4-mer - A2B1C1 Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 4-mer - A1B1C1D1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 100.42 kDa 
• Atom Count: 7411 
• Residue Count: 902 
• Unique protein chains: 4

1PYT

TERNARY COMPLEX OF PROCARBOXYPEPTIDASE A, PROPROTEINASE E, AND CHYMOTRYPSINOGEN C

• DOI: 10.2210/pdb1PYT/pdb

• Classification: TERNARY COMPLEX (ZYMOGEN)
• Organism(s): Bos taurus
• Mutation(s): No 


• Deposited: 1995-06-21 Released: 1997-01-27 
• Deposition Author(s): Gomis-Ruth, F.X., Gomez, M., Bode, W., Huber, R., Aviles, F.X.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.35 Å
• R-Value Free: 0.283 
• R-Value Work: 0.192 
• R-Value Observed: 0.192 

Literature

The three-dimensional structure of the native ternary complex of bovine pancreatic procarboxypeptidase A with proproteinase E and chymotrypsinogen C.

Gomis-Ruth, F.X., Gomez, M., Bode, W., Huber, R., Aviles, F.X.

(1995) EMBO J 14: 4387-4394

• PubMed: 7556081 
• Primary Citation of Related Structures:  
  1PYT


• PubMed Abstract: 
  

The metalloexozymogen procarboxypeptidase A is mainly secreted in ruminants as a ternary complex with zymogens of two serine endoproteinases, chymotrypsinogen C and proproteinase E. The bovine complex has been crystallized, and its molecular structure analysed and refined at 2.6 A resolution to an R factor of 0.198. In this heterotrimer, the activation segment of procarboxypeptidase A essentially clamps the other two subunits, which shield the activation sites of the former from tryptic attack. In contrast, the propeptides of both serine proproteinases are freely accessible to trypsin. This arrangement explains the sequential and delayed activation of the constituent zymogens. Procarboxypeptidase A is virtually identical to the homologous monomeric porcine form. Chymotrypsinogen C displays structural features characteristic for chymotrypsins as well as elastases, except for its activation domain; similar to bovine chymotrypsinogen A, its binding site is not properly formed, while its surface located activation segment is disordered. The proproteinase E structure is fully ordered and strikingly similar to active porcine elastase; its specificity pocket is occluded, while the activation segment is fixed to the molecular surface. This first structure of a native zymogen from the proteinase E/elastase family does not fundamentally differ from the serine proproteinases known so far.

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Related Citations: 

• Procarboxypeptidase A-S6 : Detailed Structure Analysis of the Constituting Subunits and Implications for Their Activation
  Gomis-Ruth, F.X., Gomez, M., Vendrell, J., Ventura, S., Bode, W., Huber, R., Aviles, F.X.
  () To be published --: --

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Organizational Affiliation: 

Institut de Biologia Fonamental, Universitat Autònoma de Barcelona, Bellaterra, Spain.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
PROCARBOXYPEPTIDASE A	A	94	Bos taurus	Mutation(s): 0  Gene Names: CPA1, CPA EC: 3.4.17.1
Find proteins for P00730 (Bos taurus) Explore P00730  Go to UniProtKB:  P00730

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
PROCARBOXYPEPTIDASE A	B	309	Bos taurus	Mutation(s): 0  Gene Names: CPA1, CPA EC: 3.4.17.1
Find proteins for P00730 (Bos taurus) Explore P00730  Go to UniProtKB:  P00730

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
PROPROTEINASE E	C	253	Bos taurus	Mutation(s): 0
Find proteins for P05805 (Bos taurus) Explore P05805  Go to UniProtKB:  P05805

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
CHYMOTRYPSINOGEN C	D	251	Bos taurus	Mutation(s): 0  Gene Names: CTRC EC: 3.4.21.2
Find proteins for Q7M3E1 (Bos taurus) Explore Q7M3E1  Go to UniProtKB:  Q7M3E1

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN	B	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N
CA	C	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.35 Å
• R-Value Free: 0.283 
• R-Value Work: 0.192 
• R-Value Observed: 0.192 
• Space Group: H 3

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 188.5	α = 90
b = 188.5	β = 90
c = 82.5	γ = 120

Software Package:

Software Name	Purpose
MOSFLM	data reduction
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1995-06-21 
• Released Date: 1997-01-27 
Deposition Author(s): Gomis-Ruth, F.X., Gomez, M., Bode, W., Huber, R., Aviles, F.X.

Revision History 

• Version 1.0: 1997-01-27
  Type: Initial release
  
• Version 1.1: 2008-03-03
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance