Electron transfer to the active site of the bacterial nitric oxide reductase is controlled by ligand binding to heme b3

Field, Sarah J., Roldan, M. Dolores, Marritt, Sophie J., Butt, Julea N. ORCID: https://orcid.org/0000-0002-9624-5226, Richardson, David J. ORCID: https://orcid.org/0000-0002-6847-1832 and Watmough, Nicholas J. (2011) Electron transfer to the active site of the bacterial nitric oxide reductase is controlled by ligand binding to heme b3. Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1807 (4). pp. 451-457.

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Abstract

The active site of the bacterial nitric oxide reductase from Paracoccus denitrificans contains a dinuclear centre comprising heme b3 and non heme iron (FeB). These metal centres are shown to be at isopotential with midpoint reduction potentials of Em ˜ + 80 mV. The midpoint reduction potentials of the other two metal centres in the enzyme, heme c and heme b, are greater than the dinuclear centre suggesting that they act as an electron receiving/storage module. Reduction of the low-spin heme b causes structural changes at the dinuclear centre which allow access to substrate molecules. In the presence of the substrate analogue, CO, the midpoint reduction potential of heme b3 is raised to a region similar to that of heme c and heme b. This leads us to suggest that reduction of the electron transfer hemes leads to an opening of the active site which allows substrate to bind and in turn raises the reduction potential of the active site such that electrons are only delivered to the active site following substrate binding.

Item Type: Article
Faculty \ School: Faculty of Science > School of Chemistry
Faculty of Science > School of Biological Sciences
UEA Research Groups: Faculty of Science > Research Groups > Molecular Microbiology
Faculty of Science > Research Groups > Energy Materials Laboratory
Faculty of Science > Research Groups > Chemistry of Light and Energy
Faculty of Science > Research Groups > Chemistry of Life Processes
Faculty of Science > Research Centres > Centre for Molecular and Structural Biochemistry
Faculty of Science > Research Groups > Biophysical Chemistry (former - to 2017)
Faculty of Science > Research Groups > Organisms and the Environment
Depositing User: Users 2731 not found.
Date Deposited: 14 Feb 2011 14:05
Last Modified: 15 May 2023 00:05
URI: https://ueaeprints.uea.ac.uk/id/eprint/21345
DOI: 10.1016/j.bbabio.2011.01.009

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