1CG2

CARBOXYPEPTIDASE G2

• PDB DOI: https://doi.org/10.2210/pdb1CG2/pdb

• Classification: METALLOCARBOXYPEPTIDASE
• Organism(s): Pseudomonas sp. RS-16
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 1996-12-20 Released: 1997-12-24 
• Deposition Author(s): Rowsell, S., Pauptit, R.A., Tucker, A.D., Melton, R.G., Blow, D.M., Brick, P.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 0.224 
• R-Value Work: 0.196 
• R-Value Observed: 0.196 

Literature

Crystal structure of carboxypeptidase G2, a bacterial enzyme with applications in cancer therapy.

Rowsell, S., Pauptit, R.A., Tucker, A.D., Melton, R.G., Blow, D.M., Brick, P.

(1997) Structure 5: 337-347

• PubMed: 9083113 
• DOI: https://doi.org/10.1016/s0969-2126(97)00191-3
• Primary Citation of Related Structures:  
  1CG2


• PubMed Abstract: 
  

  Carboxypeptidase G enzymes hydrolyze the C-terminal glutamate moiety from folic acid and its analogues, such as methotrexate. The enzyme studied here, carboxypeptidase G2 (CPG2), is a dimeric zinc-dependent exopeptidase produced by Pseudomonas sp. strain RS-16. CPG2 has applications in cancer therapy: following its administration as an immunoconjugate, in which CPG2 is linked to an antibody to a tumour-specific antigen, it can enzymatically convert subsequently administered inactive prodrugs to cytotoxic drugs selectively at the tumour site. CPG2 has no significant amino acid sequence homology with proteins of known structure. Hence, structure determination of CPG2 was undertaken to identify active-site residues, which may in turn provide ideas for protein and/or substrate modification with a view to improving its therapeutic usefulness.

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Organizational Affiliation: 

Blackett Laboratory, Imperial College London, SW7 2BZ, UK.

Biological Assembly 1  

Global Symmetry: Dihedral - D2  (Explore in 3D)
Global Stoichiometry: Homo 4-mer - A4 

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

Macromolecule Content

• Total Structure Weight: 167.84 kDa 
• Atom Count: 11,466 
• Modelled Residue Count: 1,556 
• Deposited Residue Count: 1,572 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
CARBOXYPEPTIDASE G2	A, B, C, D	393	Pseudomonas sp. RS-16	Mutation(s): 0  EC: 3.4.17.11
UniProt
Find proteins for P06621 (Pseudomonas sp. (strain RS-16)) Explore P06621  Go to UniProtKB:  P06621

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN	E [auth A], F [auth A], G [auth A], H [auth A], I [auth B], J [auth B], K [auth B], L [auth C], M [auth C], N [auth C], O [auth D], P [auth D], Q [auth D]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 0.224 
• R-Value Work: 0.196 
• R-Value Observed: 0.196 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 81.26	α = 90
b = 105.28	β = 109.54
c = 122.19	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
MOSFLM	data reduction
CCP4	data scaling
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1997-12-24 
Deposition Author(s): Rowsell, S., Pauptit, R.A., Tucker, A.D., Melton, R.G., Blow, D.M., Brick, P.

Revision History  

• Version 1.0: 1997-12-24
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Source and taxonomy, Version format compliance
• Version 1.3: 2024-02-14
  Changes: Data collection, Database references, Derived calculations, Other