2Q38

Carbonic Anhydrase II in complex with Saccharin at 1.95 Angstrom

• PDB DOI:  https://doi.org/10.2210/pdb2Q38/pdb

• Classification: LYASE
• Organism(s): Homo sapiens
• Mutation(s): No 


• Deposited: 2007-05-30 Released: 2007-10-02 
• Deposition Author(s): Schulze Wischeler, J., Heine, A., Klebe, G.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.95 Å
• R-Value Free: 0.260 
• R-Value Work: 0.182 
• R-Value Observed: 0.184 

Literature

Saccharin Inhibits Carbonic Anhydrases: Possible Explanation for its Unpleasant Metallic Aftertaste.

Kohler, K., Hillebrecht, A., Schulze Wischeler, J., Innocenti, A., Heine, A., Supuran, C.T., Klebe, G.

(2007) Angew Chem Int Ed Engl 46: 7697-7699

• PubMed: 17705204 
• DOI: https://doi.org/10.1002/anie.200701189
• Primary Citation of Related Structures:  
  2Q1B, 2Q38

Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 30.32 kDa 
• Atom Count: 2,322 
• Modelled Residue Count: 256 
• Deposited Residue Count: 260 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Carbonic anhydrase 2	A	260	Homo sapiens	Mutation(s): 0  Gene Names: CA2 EC: 4.2.1.1 (PDB Primary Data), 4.2.1.69 (UniProt)
UniProt & NIH Common Fund Data Resources
Find proteins for P00918 (Homo sapiens) Explore P00918  Go to UniProtKB:  P00918
PHAROS:  P00918

Small Molecules

Ligands 5 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
HG	C [auth A]	MERCURY (II) ION Hg BQPIGGFYSBELGY-UHFFFAOYSA-N
LSA	D [auth A], E [auth A]	1,2-BENZISOTHIAZOL-3(2H)-ONE 1,1-DIOXIDE C7 H5 N O3 S CVHZOJJKTDOEJC-UHFFFAOYSA-N
BEZ	F [auth A]	BENZOIC ACID C7 H6 O2 WPYMKLBDIGXBTP-UHFFFAOYSA-N
GOL	G [auth A], H [auth A], I [auth A]	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N
ZN	B [auth A]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Binding Affinity Annotations
ID	Source	Binding Affinity
LSA	PDBBind:  2Q38	Ki: 5950 (nM) from 1 assay(s)
	BindingDB:  2Q38	Ki: min: 5950, max: 5.95e+6 (nM) from 4 assay(s)
	Binding MOAD:  2Q38	Ki: 5950 (nM) from 1 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.95 Å
• R-Value Free: 0.260 
• R-Value Work: 0.182 
• R-Value Observed: 0.184 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 42.2	α = 90
b = 41.4	β = 104.6
c = 72.2	γ = 90

Software Package:

Software Name	Purpose
SHELX	model building
SHELXL-97	refinement
CrystalClear	data collection
HKL-2000	data reduction
HKL-2000	data scaling
PHASER	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2007-10-02 
Deposition Author(s): Schulze Wischeler, J., Heine, A., Klebe, G.

Revision History  

• Version 1.0: 2007-10-02
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Non-polymer description, Version format compliance
• Version 1.2: 2023-08-30
  Changes: Data collection, Database references, Derived calculations, Refinement description