1LZV

Site-Specific Mutant (Tyr7 replaced with His) of Human Carbonic Anhydrase II


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.186 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Kinetic analysis of multiple proton shuttles in the active site of human carbonic anhydrase.

Tu, C.Qian, M.An, H.Wadhwa, N.R.Duda, D.Yoshioka, C.Pathak, Y.McKenna, R.Laipis, P.J.Silverman, D.N.

(2002) J.Biol.Chem. 277: 38870-38876

  • DOI: 10.1074/jbc.M205791200

  • PubMed Abstract: 
  • We have prepared a site-specific mutant of human carbonic anhydrase (HCA) II with histidine residues at positions 7 and 64 in the active site cavity. Using a different isozyme, we have placed histidine residues in HCA III at positions 64 and 67 and i ...

    We have prepared a site-specific mutant of human carbonic anhydrase (HCA) II with histidine residues at positions 7 and 64 in the active site cavity. Using a different isozyme, we have placed histidine residues in HCA III at positions 64 and 67 and in another mutant at positions 64 and 7. Each of these histidine residues can act as a proton transfer group in catalysis when it is the only nonliganding histidine in the active site cavity, except His(7) in HCA III. Using an (18)O exchange method to measure rate constants for intramolecular proton transfer, we have found that inserting two histidine residues into the active site cavity of either isozyme II or III of carbonic anhydrase results in rates of proton transfer to the zinc-bound hydroxide that are antagonistic or suppressive with respect to the corresponding single mutants. The crystal structure of Y7H HCA II, which contains both His(7) and His(64) within the active site cavity, shows the conformation of the side chain of His(64) moved from its position in the wild type and hydrogen-bonded through an intervening water molecule with the side chain of His(7). This suggests a cause of decreased proton transfer in catalysis.


    Organizational Affiliation

    Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, Florida 32610-0267, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Carbonic Anhydrase II
A
260Homo sapiensGene 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 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.186 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 42.871α = 90.00
b = 41.585β = 104.75
c = 72.951γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
CNSphasing
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-10-23
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance