| Accession | GenProp0200 |
| Name | periplasmic nitrate reductase |
| Type | SYSTEM |
| Description | Denitrifying bacteria reduce nitrate via three distinct nitrate reductase systems. Two of these are assciated with energy-conserving electron transport systems, distinguished by cellular location and generation of a proton motive force, and the other with nitrate assimilation. All three types involve binding of molybdopterin to the active site of nitrate reductase where reduction occurs. Unlike membrane-associated nitrate reductases, periplasmic nitrate reductase cannot itself act as a coupling site for proton translocation, but can participate indirectly in respiration by virtue of the consumption of electrons derived from NADH via the proton translocating NADH dehydrogenase. Expressed aerobically as well as anearobically in gram-negative bacteria, periplasmic nitrate reductase is a two-subunit enzyme comprised of a catalytic subunit binding molybdopterin and containing a twin-arginine signal motif, and a cytochrome subunit, whose redox partner is a membrane-bound electron transfer protein. Other essential components for this denitrifying system include a proposed chaperone, and at least five other components identified in different combinations in different bacteria [1]. Lacking the membrane-bound c-type cytochrome component, in Wolinella succinogenes electron transport to nitrate reductase from one or more of these other gene products has been demonstrated [2]. |
| JCVI Role | Nitrogen metabolism |
| Parent Property | GenProp0202: nitrogen metabolism
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| Literature References | [ 1 ]Potter L, Angove H, Richardson D, Cole J. Nitrate reduction in the periplasm of gram-negative bacteria. Adv Microb Physiol. 2001;45:51-112. PMID 11450112
[ 2 ]Simon J, Sanger M, Schuster SC, Gross R. Electron transport to periplasmic nitrate reductase (NapA) of Wolinella succinogenes is independent of a NapC protein. Mol Microbiol. 2003 Jul;49(1):69-79. PMID 12823811
[ 3 ] Brondijk TH, Nilavongse A, Filenko N, Richardson DJ, Cole JA NapGH components of the periplasmic nitrate reductase of Escherichia coli K-12: location, topology and physiological roles in quinol oxidation and redox balancing. Biochem J. 2004 Apr 1;379(Pt 1):47-55. PMID 14674886
[ 4 ] Maillard J, Spronk CA, Buchanan G, Lyall V, Richardson DJ, Palmer T, Vuister GW, Sargent F Structural diversity in twin-arginine signal peptide-binding proteins. Proc Natl Acad Sci U S A. 2007 Oct 2;104(40):15641-6. PMID 17901208
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| Web References | KEGG: Nitrogen metabolism
The Ecocyc Database: nitrate reductase, periplasmic
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| Gene Ontology Term | GO:0042126: nitrate metabolic process (biological_process)
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| Step Name | Step Num | Required | Evidence (Method) | Evidence Go Terms |
|---|
| periplasmic nitrate reductase, large subunit | NapA | YES | TIGR01706 (HMM): periplasmic nitrate reductase, large subunit | GO:0042126: nitrate metabolic process
|
| nitrate reductase cytochrome c-type subunit | NapB | YES | PF03892 (HMM): periplasmic nitrate reductase, diheme cytochrome c subunit | GO:0042126: nitrate metabolic process
|
| NapC electron transfer protein | NapC | YES | TIGR02161 (HMM): periplasmic nitrate (or nitrite) reductase c-type cytochrome, NapC/NirT family | GO:0042126: nitrate metabolic process
|
| TAT signal chaperone NapD | NapD | YES | PF03927 (HMM): NapD protein | GO:0042126: nitrate metabolic process
|
| periplasmic nitrate reductase, NapE | NapE | NO | TIGR02973 (HMM): periplasmic nitrate reductase, NapE protein | GO:0042126: nitrate metabolic process
|
| ferredoxin - type protein NapF | NapF | NO | TIGR00402 (HMM): ferredoxin-type protein NapF | GO:0042126: nitrate metabolic process
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| periplasmic nitrate reductase, NapG subunit | NapG | NO | 2263 (RULE_BASE)
| GO:0042126: nitrate metabolic process
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| periplasmic nitrate reductase, NapH subunit | NapH | NO | 2262 (RULE_BASE)
| GO:0042126: nitrate metabolic process
|
