1Y7W

Crystal structure of a halotolerant carbonic anhydrase from Dunaliella salina

Summary for 1Y7W

• Entry DOI: 10.2210/pdb1y7w/pdb
• Descriptor: Halotolerant alpha-type carbonic anhydrase (dCA II), SODIUM ION, ZINC ION, ... (5 entities in total)
• Functional Keywords: alpha-type carbonic anhydrase, haltolerant protein, algal carbonic anhydrase, salt tolerant protein, zinc enzyme, anion tolerance, dunaliella salina carbonic anhydrase, dca ii, israel structural proteomics center, ispc, structural genomics, lyase
• Biological source: Dunaliella salina
• Total number of polymer chains: 2
• Total formula weight: 63770.48

Authors

Premkumar, L.,Greenblatt, H.M.,Bageshwar, U.K.,Savchenko, T.,Gokhman, I.,Sussman, J.L.,Zamir, A.,Israel Structural Proteomics Center (ISPC) (deposition date: 2004-12-10, release date: 2005-05-03, Last modification date: 2024-10-30)

Primary citation

Premkumar, L.,Greenblatt, H.M.,Bageshwar, U.K.,Savchenko, T.,Gokhman, I.,Sussman, J.L.,Zamir, A.
Three-dimensional structure of a halotolerant algal carbonic anhydrase predicts halotolerance of a mammalian homolog.
Proc.Natl.Acad.Sci.Usa, 102:7493-7498, 2005

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.

PubMed: 15894606
DOI: 10.1073/pnas.0502829102

Experimental method

X-RAY DIFFRACTION (1.86 Å)