1ZNC

HUMAN CARBONIC ANHYDRASE IV


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of the secretory form of membrane-associated human carbonic anhydrase IV at 2.8-A resolution.

Stams, T.Nair, S.K.Okuyama, T.Waheed, A.Sly, W.S.Christianson, D.W.

(1996) Proc.Natl.Acad.Sci.USA 93: 13589-13594

  • Also Cited By: 5KU6, 5JNC, 5JNA, 5JN9, 5JN8

  • PubMed Abstract: 
  • It has recently been demonstrated that the C-terminal deletion mutant of recombinant human carbonic anhydrase IV (G267X CA IV) converts the normally glycosylphosphatidylinositol-anchored enzyme into a soluble secretory form which has the same catalyt ...

    It has recently been demonstrated that the C-terminal deletion mutant of recombinant human carbonic anhydrase IV (G267X CA IV) converts the normally glycosylphosphatidylinositol-anchored enzyme into a soluble secretory form which has the same catalytic properties as the membrane-associated enzyme purified from human tissues. We have determined the three-dimensional structure of the secretory form of human CA IV by x-ray crystallographic methods to a resolution of 2.8 A. Although the zinc binding site and the hydrophobic substrate binding pocket of CA IV are generally similar to those of other mammalian isozymes, unique structural differences are found elsewhere in the active site. Two disufide linkages, Cys-6-Cys-11G and Cys-23-Cys-203, stabilize the conformation of the N-terminal domain. The latter disulfide additionally stabilizes an active site loop containing a cis-peptide linkage between Pro-201 and Thr-202 (this loop contains catalytic residue Thr-199). On the opposite side of the active site, the Val-131-Asp-136 segment adopts an extended loop conformation instead of an alpha-helix conformation as found in other isozymes. Finally, the C terminus is surrounded by a substantial electropositive surface potential, which is likely to stabilize the interaction of CA IV with the negatively charged phospholipid headgroups of the membrane. These structural features are unique to CA IV and provide a framework for the design of sulfonamide inhibitors selective for this particular isozyme.


    Related Citations: 
    • Carbonic Anhydrase Iv: Purification of a Secretory Form of the Recombinant Human Enzyme and Identification of the Positions and Importance of its Disulfide Bonds
      Waheed, A.,Okuyama, T.,Heyduk, T.,Sly, W.S.
      (1996) Arch.Biochem.Biophys. 333: 432


    Organizational Affiliation

    Department of Chemistry, University of Pennsylvania, Philadelphia 19104-6323, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CARBONIC ANHYDRASE IV
A, B
266Homo sapiensMutation(s): 0 
Gene Names: CA4
EC: 4.2.1.1
Find proteins for P22748 (Homo sapiens)
Go to Gene View: CA4
Go to UniProtKB:  P22748
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
SO4Ki: 9000000 - 44000000 nM (100) BINDINGDB
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.197 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 89.500α = 90.00
b = 47.700β = 106.30
c = 141.000γ = 90.00
Software Package:
Software NamePurpose
X-PLORrefinement
X-PLORphasing
MOSFLMdata reduction
X-PLORmodel building
ROTAVATA/AGROVATAdata reduction
ROTAVATA)data scaling
CCP4data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1997-09-17
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance