Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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

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

Macromolecule Content

• Total Structure Weight: 30.11 kDa 
• Atom Count: 2536 
• Residue Count: 257 
• Unique protein chains: 1

3HS4

Human carbonic anhydrase II complexed with acetazolamide

• DOI: 10.2210/pdb3HS4/pdb

• Classification: LYASE
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2009-06-10 Released: 2009-12-08 
• Deposition Author(s): Robbins, A.H., Genis, C., Domsic, J., Sippel, K.H., Agbandje-McKenna, M., McKenna, R.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.10 Å
• R-Value Free: 0.140 
• R-Value Work: 0.112 
• R-Value Observed: 0.113 

Literature

High-resolution structure of human carbonic anhydrase II complexed with acetazolamide reveals insights into inhibitor drug design.

Sippel, K.H., Robbins, A.H., Domsic, J., Genis, C., Agbandje-McKenna, M., McKenna, R.

(2009) Acta Crystallogr Sect F Struct Biol Cryst Commun 65: 992-995

• PubMed: 19851004 
• DOI: 10.1107/S1744309109036665
• Structures With Same Primary Citation


• PubMed Abstract: 
  

The crystal structure of human carbonic anhydrase II (CA II) complexed with the inhibitor acetazolamide (AZM) has been determined at 1.1 A resolution and refined to an R(cryst) of 11.2% and an R(free) of 14.7%. As observed in previous CA II-inhibitor complexes, AZM binds directly to the zinc and makes several key interactions with active-site residues. The high-resolution data also showed a glycerol molecule adjacent to the AZM in the active site and two additional AZMs that are adventitiously bound on the surface of the enzyme. The co-binding of AZM and glycerol in the active site demonstrate that given an appropriate ring orientation and substituents, an isozyme-specific CA inhibitor may be developed.

---

Related Citations: 

• Refined structure of the acetazolamide complex of human carbonic anhydrase II at 1.9 A.
  Vidgren, J., Liljas, A., Walker, N.P.
  (1990) Int J Biol Macromol 12: 342

---

Organizational Affiliation: 

Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Carbonic anhydrase 2	A	260	Homo sapiens	Mutation(s): 0  Gene Names: CA2 EC: 4.2.1.1
Find proteins for P00918 (Homo sapiens) Go to UniProtKB:  P00918
NIH Common Fund Data Resources
PHAROS  P00918 GTEx  ENSG00000104267

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
AZM	A	5-ACETAMIDO-1,3,4-THIADIAZOLE-2-SULFONAMIDE C4 H6 N4 O3 S2 BZKPWHYZMXOIDC-UHFFFAOYSA-N
GOL	A	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N
ZN	A	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

External Ligand Annotations
ID	Binding Affinity (Sequence Identity %)
AZM	Ki:  10   nM  Binding MOAD
AZM	Ki :  10   nM  PDBBind

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.10 Å
• R-Value Free: 0.140 
• R-Value Work: 0.112 
• R-Value Observed: 0.113 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 42.252	α = 90
b = 41.097	β = 104.31
c = 71.82	γ = 90

Software Package:

Software Name	Purpose
SHELXL-97	refinement
CNS	refinement
ADSC	data collection
HKL-2000	data reduction
HKL-2000	data scaling
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2009-06-10 
• Released Date: 2009-12-08 
Deposition Author(s): Robbins, A.H., Genis, C., Domsic, J., Sippel, K.H., Agbandje-McKenna, M., McKenna, R.

Revision History 

• Version 1.0: 2009-12-08
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Non-polymer description, Version format compliance
• Version 1.2: 2019-07-24
  Changes: Data collection, Refinement description