1AVN

HUMAN CARBONIC ANHYDRASE II COMPLEXED WITH THE HISTAMINE ACTIVATOR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Work: 0.154 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Carbonic anhydrase activators: X-ray crystallographic and spectroscopic investigations for the interaction of isozymes I and II with histamine.

Briganti, F.Mangani, S.Orioli, P.Scozzafava, A.Vernaglione, G.Supuran, C.T.

(1997) Biochemistry 36: 10384-10392

  • DOI: 10.1021/bi970760v

  • PubMed Abstract: 
  • The interaction of native and Co(II)-substituted isozymes I and II of carbonic anhydrase (CA) with histamine, a well-known activator, was investigated kinetically, spectroscopically, and X-ray crystallographically. This activator is of the noncompeti ...

    The interaction of native and Co(II)-substituted isozymes I and II of carbonic anhydrase (CA) with histamine, a well-known activator, was investigated kinetically, spectroscopically, and X-ray crystallographically. This activator is of the noncompetitive type with 4-nitrophenyl acetate and CO2 as substrates for both HCA I and HCA II. The electronic spectrum of the adduct of Co(II)-HCA II with histamine is similar to the spectrum of the Co(II)-HCA II-phenol adduct, being only slightly different from that of the uncomplexed enzyme. This is the first spectroscopic evidence that the activator molecule binds within the active site, but not directly to the metal ion. X-ray crystallographic data for the adduct of HCA II with histamine showed that the activator molecule is bound at the entrance of the active site cavity in a position where it may actively participate in shuttling protons between the active site and the bulk solvent. The role of the activators and the reported X-ray crystal structure of the HCA II-histamine adduct has prompted us to reexamine the X-ray structures of the different CA isozymes in order to find a structural basis accounting for their large differences in catalytic rate. A tentative explanation is proposed on the basis of possible pathways of proton transfer, which constitute the rate-limiting step in the catalytic reaction.


    Organizational Affiliation

    Dipartimento di Chimica, Laboratorio di Chimica Inorganica e Bioinorganica, Università degli Studi, Via Gino Capponi 7, 50121 Firenze, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CARBONIC ANHYDRASE II
A
259Homo sapiensMutation(s): 0 
Gene Names: CA2
EC: 4.2.1.1
Find proteins for P00918 (Homo sapiens)
Go to Gene View: CA2
Go to UniProtKB:  P00918
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

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Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
AZI
Query on AZI

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Download CCD File 
A
AZIDE ION
N3
IVRMZWNICZWHMI-UHFFFAOYSA-N
 Ligand Interaction
HSM
Query on HSM

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Download CCD File 
A
HISTAMINE
C5 H9 N3
NTYJJOPFIAHURM-UHFFFAOYSA-N
 Ligand Interaction
HG
Query on HG

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Download CCD File 
A
MERCURY (II) ION
Hg
BQPIGGFYSBELGY-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
HSMKd: 125000 nM BINDINGMOAD
HSMKd: 125000 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Work: 0.154 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 42.610α = 90.00
b = 41.690β = 104.24
c = 72.780γ = 90.00
Software Package:
Software NamePurpose
XENGENdata reduction
CCP4refinement
XENGENdata scaling
CCP4phasing
CCP4model building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1997-12-24
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-11-29
    Type: Advisory, Derived calculations, Other
  • Version 1.4: 2018-04-04
    Type: Data collection