4E5Q

Human Carbonic Anhydrase II in complex with cyanate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.174 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Human carbonic anhydrase II-cyanate inhibitor complex: putting the debate to rest.

West, D.Pinard, M.A.Tu, C.Silverman, D.N.McKenna, R.

(2014) Acta Crystallogr Sect F Struct Biol Cryst Commun 70: 1324-1327

  • DOI: https://doi.org/10.1107/S2053230X14018135
  • Primary Citation of Related Structures:  
    4E5Q, 4QEF

  • PubMed Abstract: 

    The binding of anions to carbonic anhydrase II (CA II) has been attributed to high affinity for the active-site zinc. An anion of interest is cyanate, for which contrasting binding modes have been reported in the literature. Previous spectroscopic data have shown cyanate behaving as an inhibitor, directly binding to the zinc, in contrast to previous crystallographic data that implied that cyanate acts as a substrate mimic that is not directly bound to the zinc but overlaps with the binding site of the substrate CO2. Wild-type and the V207I variant of CA II have been expressed and X-ray crystal structures of their cyanate complexes have been determined to 1.7 and 1.5 Å resolution, respectively. The rationale for the V207I CA II variant was its close proximity to the CO2-binding site. Both structures clearly show that the cyanate binds directly to the zinc. In addition, inhibition constants (∼40 µM) were measured using (18)O-exchange mass spectrometry for wild-type and V207I CA II and were similar to those determined previously (Supuran et al., 1997). Hence, it is concluded that under the conditions of these experiments the binding of cyanate to CA II is directly to the zinc, displacing the zinc-bound solvent molecule, and not in a site that overlaps with the CO2 substrate-binding site.


  • Organizational Affiliation

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


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Carbonic anhydrase 2260Homo sapiensMutation(s): 0 
Gene Names: CA2
EC: 4.2.1.1
UniProt & NIH Common Fund Data Resources
Find proteins for P00918 (Homo sapiens)
Explore P00918 
Go to UniProtKB:  P00918
PHAROS:  P00918
GTEx:  ENSG00000104267 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00918
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
0NM BindingDB:  4E5Q Ki: 3.00e+4 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.174 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.192α = 90
b = 41.01β = 104.51
c = 71.536γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
CrystalCleardata collection
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-03-27
    Type: Initial release
  • Version 1.1: 2014-10-08
    Changes: Database references
  • Version 1.2: 2014-10-22
    Changes: Database references
  • Version 1.3: 2017-11-15
    Changes: Refinement description
  • Version 1.4: 2023-09-13
    Changes: Data collection, Database references, Derived calculations, Refinement description