1Z97

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.186 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

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

  • DOI: 10.1021/bi050610h
  • Primary Citation of Related Structures:  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 ...

    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.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Carbonic anhydrase III
A
266Homo sapiensGene Names: CA3
EC: 4.2.1.1
Find proteins for P07451 (Homo sapiens)
Go to Gene View: CA3
Go to UniProtKB:  P07451
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.186 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 44.105α = 90.00
b = 70.775β = 115.07
c = 44.487γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
SCALEPACKdata scaling
CNSphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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