1Y7W

Crystal structure of a halotolerant carbonic anhydrase from Dunaliella salina


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.86 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.194 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Three-dimensional structure of a halotolerant algal carbonic anhydrase predicts halotolerance of a mammalian homolog.

Premkumar, L.Greenblatt, H.M.Bageshwar, U.K.Savchenko, T.Gokhman, I.Sussman, J.L.Zamir, A.

(2005) Proc Natl Acad Sci U S A 102: 7493-7498

  • DOI: https://doi.org/10.1073/pnas.0502829102
  • Primary Citation of Related Structures:  
    1Y7W

  • PubMed Abstract: 

    Protein molecular adaptation to drastically shifting salinities was studied in dCA II, an alpha-type carbonic anhydrase (EC 4.2.1.1) from the exceptionally salt-tolerant unicellular green alga Dunaliella salina. The salt-inducible, extracellular dCA II is highly salt-tolerant and thus differs from its mesophilic homologs. The crystal structure of dCA II, determined at 1.86-A resolution, is globally similar to other alpha-type carbonic anhydrases except for two extended alpha-helices and an added Na-binding loop. Its unusual electrostatic properties include a uniformly negative surface electrostatic potential of lower magnitude than that observed in the highly acidic halophilic proteins and an exceptionally low positive potential at a site adjoining the catalytic Zn(2+) compared with mesophilic homologs. The halotolerant dCA II also differs from typical halophilic proteins in retaining conformational stability and solubility in low to high salt concentrations. The crucial role of electrostatic features in dCA II halotolerance is strongly supported by the ability to predict the unanticipated halotolerance of the murine CA XIV isozyme, which was confirmed biochemically. A proposal for the functional significance of the halotolerance of CA XIV in the kidney is presented.


  • Organizational Affiliation

    Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Halotolerant alpha-type carbonic anhydrase (dCA II)
A, B
291Dunaliella salinaMutation(s): 0 
Gene Names: dCA II
EC: 4.2.1.1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.86 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.194 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.022α = 90
b = 119.835β = 94.549
c = 58.442γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
CNSrefinement
CNSphasing

Structure Validation

View Full Validation Report



Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2005-05-03
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2023-08-23
    Changes: Data collection, Database references, Derived calculations, Refinement description