title: An electrogenic nitric oxide reductase.
abstract: Nitric oxide reductases (Nors) are members of the heme-copper oxidase superfamily that reduce nitric oxide (NO) to nitrous oxide (N₂O). In contrast to the proton-pumping cytochrome oxidases, Nors studied so far have neither been implicated in proton pumping nor have they been experimentally established as electrogenic. The copper-A-dependent Nor from Bacillus azotoformans uses cytochrome c₅₅₁ as electron donor but lacks menaquinol activity, in contrast to our earlier report (Suharti et al., 2001). Employing reduced phenazine ethosulfate (PESH) as electron donor, the main NO reduction pathway catalyzed by Cu(A)Nor reconstituted in liposomes involves transmembrane cycling of the PES radical. We show that Cu(A)Nor reconstituted in liposomes generates a proton electrochemical gradient across the membrane similar in magnitude to cytochrome aa₃, highlighting that bacilli using Cu(A)Nor can exploit NO reduction for increased cellular ATP production compared to organisms using cNor.
authors.affiliation: Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC, The Netherlands.
authors.forename: Sinan
authors.initials: S
authors.lastname: Al-Attar
authors.affiliation: Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC, The Netherlands. Electronic address: S.deVries@tudelft.nl.
authors.forename: Simon
authors.initials: S
authors.lastname: de Vries
mesh_terms: D001407:Bacillus / Q000201:enzymology* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D055162:Biocatalysis / Q000187:drug effects; D003300:Copper / Q000737:chemistry; D006420:Hemeproteins / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008081:Liposomes; D008564:Membrane Potentials / Q000187:drug effects; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D008667:Metalloproteins / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D009569:Nitric Oxide / Q000378:metabolism*; D009586:Nitrogen Fixation; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D010231:Paracoccus denitrificans / Q000201:enzymology / Q000378:metabolism; D010619:Phenazines / Q000494:pharmacology; D011487:Protein Conformation; D019163:Reducing Agents / Q000494:pharmacology; D009626:Terminology as Topic
chemical_list: D001426:Bacterial Proteins; D006420:Hemeproteins; D008081:Liposomes; D008565:Membrane Proteins; D008667:Metalloproteins; D010619:Phenazines; D019163:Reducing Agents; C028122:5-ethylphenazine; D009569:Nitric Oxide; D003300:Copper; D010088:Oxidoreductases; C034747:nitric-oxide reductase
keywords: Denitrification; Electrogenic; Membrane potential; Nitric oxide; Nitric oxide reductase