1CAO

CRYSTALLOGRAPHIC STUDIES OF THE BINDING OF PROTONATED AND UNPROTONATED INHIBITORS TO CARBONIC ANHYDRASE USING HYDROGEN SULPHIDE AND NITRATE ANIONS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Observed: 0.146 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Crystallographic studies of the binding of protonated and unprotonated inhibitors to carbonic anhydrase using hydrogen sulphide and nitrate anions.

Mangani, S.Hakansson, K.

(1992) Eur J Biochem 210: 867-871

  • DOI: 10.1111/j.1432-1033.1992.tb17490.x
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • The structures of human carbonic-anhydrase-II complexes with the anionic inhibitors hydrogen sulphide (HS-) and nitrate (NO3-) have been determined by X-ray diffraction at 0.19-nm resolution from crystals soaked at pH 7.8 and 6.0, respectively. The m ...

    The structures of human carbonic-anhydrase-II complexes with the anionic inhibitors hydrogen sulphide (HS-) and nitrate (NO3-) have been determined by X-ray diffraction at 0.19-nm resolution from crystals soaked at pH 7.8 and 6.0, respectively. The modes of binding of these two anions differ markedly from each other. The strong inhibitor HS- replaces the native zinc-bound water/hydroxide (Wat263) leaving the tetrahedral metal geometry unaltered and acts as a hydrogen-bonding donor towards Thr199 gamma. The weak NO3- inhibitor does not displace Wat263 from the metal coordination but occupies a fifth binding site changing the zinc coordination polyhedron into a slightly distorted trigonal bipyramid. The interaction of NO3- with the metal is weak; the nearest of its oxygen atoms being at a distance of 0.28 nm from the zinc ion. The binding of nitrate to the enzyme is completed by a hydrogen bond to the metal coordinated Wat263 and a second one to a water molecule of the active-site cavity. The structures of the two complexes help to rationalize the binding of anionic inhibitors to carbonic anhydrase and the binding mode displayed by NO39 may be relevant to the catalytic mechanism.


    Organizational Affiliation

    Chemistry Department, University of Siena, Italy.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CARBONIC ANHYDRASE II
A
260Homo sapiensMutation(s): 0 
Gene Names: CA2
EC: 4.2.1.1
Find proteins for P00918 (Homo sapiens)
Go to UniProtKB:  P00918
NIH Common Fund Data Resources
PHAROS  P00918
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
H2S
Query on H2S

Download CCD File 
A
HYDROSULFURIC ACID
H2 S
RWSOTUBLDIXVET-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Observed: 0.146 
  • 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
PROFFTrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1994-01-31
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Derived calculations, Other