Structural investigation of the molybdenum site of the periplasmic nitrate reductase from Thiosphaera pantotropha by X-ray absorption spectroscopy

Bennett, Brian, Charnock, John M., Sears, Heather J., Berks, Ben C., Thomson, Andrew J., Ferguson, Stuart J., Garner, C. David and Richardson, David J. ORCID: https://orcid.org/0000-0002-6847-1832 (1996) Structural investigation of the molybdenum site of the periplasmic nitrate reductase from Thiosphaera pantotropha by X-ray absorption spectroscopy. Biochemical Journal, 317 (2). pp. 557-563. ISSN 0264-6021

Full text not available from this repository. (Request a copy)

Abstract

The molybdenum centre of the periplasmic respiratory nitrate reductase from the denitrifying bacterium Thiosphaera pantotropha has been probed using molybdenum K-edge X-ray absorption spectroscopy. The optimum fit of the Mo(VI) EXAFS suggests two = O, three -S- and either a fourth -S- or an -O-/-N- as molybdenum ligands in the ferricyanide-oxidized enzyme. Three of the -S- ligands are proposed to be the two sulphur atoms of the molybdopterin dithiolene group and Cys-181. Comparison of the EXAFS of the ferricyanide-oxidized enzyme with that of a nitrate-treated sample containing 30% Mo(V) suggests that the Mo(VI) → Mo(V) reduction is accompanied by conversion of one = O to -O-. The best fit to the Mo(IV) EXAFS of dithionite-reduced enzyme was obtained using one = O, one -O- and four -S-/-Cl ligands. The periplasmic nitrate reductase molybdenum co-ordination environment in both the Mo(VI) and Mo(IV) oxidation states is distinct from that found in the membrane-bound respiratory nitrate reductase.

Item Type: Article
Uncontrolled Keywords: biochemistry,molecular biology,cell biology ,/dk/atira/pure/subjectarea/asjc/1300/1303
Faculty \ School:
Faculty of Science > School of Biological Sciences
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 14 Jul 2022 17:30
Last Modified: 12 Aug 2022 05:35
URI: https://ueaeprints.uea.ac.uk/id/eprint/86140
DOI: 10.1042/bj3170557

Actions (login required)

View Item View Item