1CVA

STRUCTURAL AND FUNCTIONAL IMPORTANCE OF A CONSERVED HYDROGEN BOND NETWORK IN HUMAN CARBONIC ANHYDRASE II


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Observed: 0.173 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural and functional importance of a conserved hydrogen bond network in human carbonic anhydrase II.

Krebs, J.F.Ippolito, J.A.Christianson, D.W.Fierke, C.A.

(1993) J Biol Chem 268: 27458-27466

  • Primary Citation of Related Structures:  
    1CVA, 1CVB

  • PubMed Abstract: 
  • Amino acid substitutions at Thr199 of human carbonic anhydrase II (CAII) (Thr199-->Ser, Ala, Val, and Pro) were characterized to investigate the importance of a conserved hydrogen bonding network. The three-dimensional structures of azide-bound and sulfate-bound T199V CAIIs were determined by x-ray crystallographic methods at 2 ...

    Amino acid substitutions at Thr199 of human carbonic anhydrase II (CAII) (Thr199-->Ser, Ala, Val, and Pro) were characterized to investigate the importance of a conserved hydrogen bonding network. The three-dimensional structures of azide-bound and sulfate-bound T199V CAIIs were determined by x-ray crystallographic methods at 2.25 and 2.4 A, respectively (final crystallographic R factors are 0.173 and 0.174, respectively). The CO2 hydrase activities of T199S and T199P variants suggest that the side chain methyl and backbone amino functionalities stabilize the transition state by approximately 0.4 and 0.8 kcal/mol, respectively. The side chain hydroxyl group causes: stabilization of zinc-hydroxide relative to zinc-water (pKa increases approximately 2 units); stabilization of the transition state for bicarbonate dehydration relative to the CAII.HCO3- complex (approximately 5 kcal/mol); and destabilization of the CAII.HCO3- complex (approximately 0.8 kcal/mol). An inverse correlation between log(kcatCO2/KM) and the pKa of zinc-water (r = 0.95, slope = -1) indicates that the hydrogen bonding network stabilizes the chemical transition state and zinc-hydroxide similarly. These data are consistent with the hydroxyl group of Thr199 forming a hydrogen bond with the transition state and a non-hydrogen-bonded van der Waals contact with CAII.HCO3-.


    Organizational Affiliation

    Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CARBONIC ANHYDRASE IIA259Homo sapiensMutation(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
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00918
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download Ideal Coordinates CCD File 
B [auth A]ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
AZI
Query on AZI

Download Ideal Coordinates CCD File 
C [auth A]AZIDE ION
N3
IVRMZWNICZWHMI-UHFFFAOYSA-N
 Ligand Interaction
Binding Affinity Annotations 
IDSourceBinding Affinity
AZI BindingDB:  1CVA Ki: min: 1.50e+6, max: 1.51e+6 (nM) from 2 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Observed: 0.173 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.7α = 90
b = 41.7β = 104.6
c = 73γ = 90
Software Package:
Software NamePurpose
PROLSQrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1993-10-31
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Derived calculations, Other