Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 30.48 kDa 
• Atom Count: 2237 
• Modelled Residue Count: 263 
• Deposited Residue Count: 266 
• Unique protein chains: 1

1Z93

Human Carbonic Anhydrase III:Structural and Kinetic study of Catalysis and Proton Transfer.

• DOI: 10.2210/pdb1Z93/pdb

• Classification: LYASE
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2005-03-31 Released: 2005-08-09 
• Deposition Author(s): Duda, D.M., Tu, C., Fisher, S.Z., An, H., Yoshioka, C., Govindasamy, L., Laipis, P.J., Agbandje-McKenna, M., Silverman, D.N., McKenna, R.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.10 Å
• R-Value Free: 0.258 
• R-Value Work: 0.205 

Literature

Human Carbonic Anhydrase III: Structural and Kinetic Study of Catalysis and Proton Transfer

Duda, D.M., Tu, C., Fisher, S.Z., An, H., Yoshioka, C., Govindasamy, L., Laipis, P.J., Agbandje-McKenna, M., Silverman, D.N., McKenna, R.

(2005) Biochemistry 44: 10046-10053

• PubMed: 16042381 
• DOI: 10.1021/bi050610h
• Primary Citation of Related Structures:  
  1Z97, 1Z93


• PubMed Abstract: 
  

The residue phenylalanine 198 (Phe 198) is a prominent cause of the lower activity of human carbonic anhydrase III (HCA III) compared with HCA II and other isozymes which have leucine at this site. We report the crystal structures of HCA III and the site-directed mutant F198L HCA III, both at 2.1 A resolution, and the enhancement of catalytic activity by exogenous proton donors containing imidazole rings. Both enzymes had a hexahistidine extension at the carboxy-terminal end, used to aid in purification, that was ordered in the crystal structures bound in the active site cavity of an adjacent symmetry-related enzyme. This observation allowed us to comment on a number of possible binding sites for imidazole and derivatives as exogenous proton donors/acceptors in catalysis by HCA III. Kinetic and structural evidence indicates that the phenyl side chain of Phe 198 in HCA III, about 5 A from the zinc, is a steric constriction in the active site, may cause altered interactions at the zinc-bound solvent, and is a binding site for the activation of catalysis by histidylhistidine. This suggests that sites of activation of the proton-transfer pathway in carbonic anhydrase are closer to the zinc than considered in previous studies.

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Organizational Affiliation: 

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

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Carbonic anhydrase III	A	266	Homo sapiens	Mutation(s): 2  Gene Names: CA3 EC: 4.2.1.1
UniProt & NIH Common Fund Data Resources
Find proteins for P07451 (Homo sapiens) Explore P07451  Go to UniProtKB:  P07451
PHAROS:  P07451 GTEx:  ENSG00000164879

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN	B [auth A]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.10 Å
• R-Value Free: 0.258 
• R-Value Work: 0.205 
• Space Group: P 6₅

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 44.7	α = 90
b = 44.7	β = 90
c = 222.557	γ = 120

Software Package:

Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
CNS	refinement
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2005-03-31 
• Released Date: 2005-08-09 
Deposition Author(s): Duda, D.M., Tu, C., Fisher, S.Z., An, H., Yoshioka, C., Govindasamy, L., Laipis, P.J., Agbandje-McKenna, M., Silverman, D.N., McKenna, R.

Revision History  

• Version 1.0: 2005-08-09
  Type: Initial release
  
• Version 1.1: 2008-04-30
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance