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 June 14, 1996 | public
Journal Article

Crystal Structure of DMSO Reductase: Redox-Linked Changes in Molybdopterin Coordination

Abstract

The molybdoenzyme dimethylsulfoxide (DMSO) reductase contributes to the release of dimethylsulfide, a compound that has been implicated in cloud nucleation and global climate regulation. The crystal structure of DMSO reductase from Rhodobacter sphaeroides reveals a monooxo molybdenum cofactor containing two molybdopterin guanine dinucleotides that asymmetrically coordinate the molybdenum through their dithiolene groups. One of the pterins exhibits different coordination modes to the molybdenum between the oxidized and reduced states, whereas the side chain oxygen of Ser^(147) coordinates the metal in both states. The change in pterin coordination between the Mo(VI) and Mo(IV) forms suggests a mechanism for substrate binding and reduction by this enzyme. Sequence comparisons of DMSO reductase with a family of bacterial oxotransferases containing molybdopterin guanine dinucleotide indicate a similar polypeptide fold and active site with two molybdopterins within this family.

Additional Information

© 1996 American Association for the Advancement of Science. 15 January 1996: Accepted 23 April 1996. We thank J. Enemark for insightful discussions and suggestions on the manuscript. Supported by Deutsche Forschungsgemeinschaft postdoctoral fellowships (to C.K. and H.S.), by USPHS grant GM50775 (D.C.R.), and by USPHS grant GM00091 (K.V.R.). The rotation camera facility at SSRL is supported by the Department of Energy and NIH. The X-PLOR calculations were performed on the CRAY C90 at the San Diego Supercomputer Center, supported by the NSF. Coordinates have been deposited in the Brookhaven Protein Data Bank and can be supplied by e-mail to hermann@citray.caltech.edu.

Additional details

Created:
August 19, 2023
Modified:
October 19, 2023