The Active Site Structure ofThalassiosira weissflogiiCarbonic Anhydrase 1†

Elizabeth H. Cox, George L. McLendon, François M. M. Morel, Todd W. Lane, Roger C. Prince, Ingrid J. Pickering, Graham N. George
2000 Biochemistry  
X-ray absorption spectroscopy at the Zn K-edge indicates that the active site of the marine diatom Thalassiosira weissflogii carbonic anhydrase is strikingly similar to that of mammalian R-carbonic anhydrase enzymes. The zinc has three histidine ligands and a single water at 1.98 Å. This is quite different from the -carbonic anhydrases of higher plants in which zinc is coordinated by two cysteine thiolates, one histidine, and a water molecule. The diatom carbonic anhydrase shows no significant
more » ... ows no significant sequence similarity with other carbonic anhydrases and may represent an example of convergent evolution at the molecular level.
doi:10.1021/bi001416s pmid:11015190 fatcat:ifeif6adlzbwrj4rrnmxx2stcq