Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published March 30, 2001 | public
Journal Article

Crystal Structure of the "cab"-type β Class Carbonic Anhydrase from the Archaeon Methanobacterium thermoautotrophicum


The structure of the "cab"-type β class carbonic anhydrase from the archaeon Methanobacterium thermoautotrophicum (Cab) has been determined to 2.1-Å resolution using the multiwavelength anomalous diffraction phasing technique. Cab exists as a dimer with a subunit fold similar to that observed in "plant"-type β class carbonic anhydrases. The active site zinc is coordinated by protein ligands Cys^(32), His^(87), and Cys^(90), with the tetrahedral coordination completed by a water molecule. The major difference between plant- and cab-type β class carbonic anhydrases is in the organization of the hydrophobic pocket. The structure reveals a Hepes buffer molecule bound 8 Å away from the active site zinc, which suggests a possible proton transfer pathway from the active site to the solvent.

Additional Information

© 2001 by The American Society for Biochemistry and Molecular Biology, Inc. Received for publication, October 9, 2000, and in revised form, November 26, 2000. First Published on November 28, 2000. This work was supported by National Institutes of Health Grants GM44661 (to J. G. F) and GM45162 (to D. C. R.); a National Science Foundation predoctoral fellowship (to P. S.); and NASA-AMES Cooperative Agreement NCC2-1057 (to the Pennsylvania State University Astrobiology Research Center). This work is based upon research conducted at the Stanford Synchrotron Radiation Laboratory, which is funded by the Department of Energy (Office of Basic Energy Sciences and Office of Biological and Environmental Research) and the National Institutes of Health (National Center for Research Resources, NIGMS). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. We thank Jessica Wuu and Radu Georgescu for help with crystallizations and Brian R. Crane and Alex M. Bilwes for help with data collection.

Additional details

August 19, 2023
October 19, 2023