Surface residue engineering of bovine carbonic anhydrase to an extreme halophilic enzyme for potential application in postcombustion CO2 capture

Experimental Data Snapshot

  • Resolution: 1.23 Å
  • R-Value Free: 0.147 
  • R-Value Work: 0.111 
  • R-Value Observed: 0.112 

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This is version 1.3 of the entry. See complete history


Rational Engineering of a Mesohalophilic Carbonic Anhydrase to an Extreme Halotolerant Biocatalyst.

Warden, A.C.Williams, M.Peat, T.S.Seabrook, S.A.Newman, J.Dojchinov, G.Haritos, V.S.

(2015) Nat Commun 6: 10278

  • DOI: https://doi.org/10.1038/ncomms10278
  • Primary Citation of Related Structures:  
    4CNR, 4CNV, 4CNW, 4CNX, 5A25

  • PubMed Abstract: 

    Enzymes expressed by highly salt-tolerant organisms show many modifications compared with salt-affected counterparts including biased amino acid and lower α-helix content, lower solvent accessibility and negative surface charge. Here, we show that halotolerance can be generated in an enzyme solely by modifying surface residues. Rational design of carbonic anhydrase II is undertaken in three stages replacing 18 residues in total, crystal structures confirm changes are confined to surface residues. Catalytic activities and thermal unfolding temperatures of the designed enzymes increase at high salt concentrations demonstrating their shift to halotolerance, whereas the opposite response is found in the wild-type enzyme. Molecular dynamics calculations reveal a key role for sodium ions in increasing halotolerant enzyme stability largely through interactions with the highly ordered first Na(+) hydration shell. For the first time, an approach to generate extreme halotolerance, a trait with broad application in industrial biocatalysis, in a wild-type enzyme is demonstrated.

  • Organizational Affiliation

    Energy Flagship, Commonwealth Scientific and Industrial Research Organisation (CSIRO), GPO Box 1700, Canberra, Australian Capital Territory 2601, Australia.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
CARBONIC ANHYDRASE 2262Bos taurusMutation(s): 18 
Find proteins for P00921 (Bos taurus)
Explore P00921 
Go to UniProtKB:  P00921
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00921
Sequence Annotations
  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Resolution: 1.23 Å
  • R-Value Free: 0.147 
  • R-Value Work: 0.111 
  • R-Value Observed: 0.112 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 41.591α = 90
b = 67.937β = 103.07
c = 43.134γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-02-04
    Type: Initial release
  • Version 1.1: 2016-01-13
    Changes: Database references
  • Version 1.2: 2019-05-15
    Changes: Data collection, Experimental preparation, Other
  • Version 1.3: 2023-12-20
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description