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Crystal structure of DMSO reductase: Redox-linked changes in molybdopterin coordination

Journal Article · · Science
; ;  [1]; ;  [2]
  1. California Institute of Technology, Pasadena, CA (United States)
  2. Duke Univ., Durham, NC (United States)
The molybdoenzyme dimethysulfoxide (DMSO) reductase contributes to the release of dimethysulfide, 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{sup 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. 51 refs., 7 figs., 1 tab.
Sponsoring Organization:
USDOE
OSTI ID:
426163
Journal Information:
Science, Journal Name: Science Journal Issue: 5268 Vol. 272; ISSN SCIEAS; ISSN 0036-8075
Country of Publication:
United States
Language:
English