What is the purpose of the enzyme nitrate reductase?
Nitrate reductase (NR; EC 1.6. 6.1-3) catalyzes NAD(P)H reduction of nitrate to nitrite. NR serves plants, algae, and fungi as a central point for integration of metabolism by governing flux of reduced nitrogen by several regulatory mechanisms.
What inhibits nitrate reductase?
Nitrate reductase is inhibited by phosphorylation of a serine residue and the subsequent interaction with an inhibitor protein. Okadaic acid, an inhibitor of protein phosphatases, counteracts the activation of nitrate reductase. (After Huber et al., 1996.)
What activates nitrate reductase?
Fe mineral element controls the activity of Nitrate reductase.
What enzyme is responsible for nitrate reduction?
nitrate reductase
Assimilatory nitrate reductase is an enzyme of the assimilative metabolism involved in reduction of nitrate to nitrite. The nitrite is immediately reduced to ammonia (probably via hydroxylamine) by the activity of nitrite reductase.
How is nitrate reductase regulated?
Nitrate reductase (NR) is regulated at the transcriptional and translational levels induced by light, nitrate, and possibly a negative feedback mechanism.
Do humans have nitrate reductase?
Bacteria express nitrate reductases that produce nitrite, but mammals lack these specific enzymes. Here we report on nitrate reductase activity in rodent and human tissues that results in formation of nitrite and nitric oxide (NO) and is attenuated by the xanthine oxidoreductase inhibitor allopurinol.
Does E coli reduce nitrate to nitrite?
1 Introduction. In the absence of oxygen, Escherichia coli K-12 will preferentially use nitrate as a terminal electron acceptor for anaerobic growth. Nitrate is reduced to nitrite by three genetically and biochemically distinct enzymes.
Which element activates the enzyme nitrate reductase during the nitrogen fixation?
Molybdenum (Mo) aids in nitrogen-fixation, as it is an activator of nitrate reductase and a constituent of enzyme nitrogenase.
Does nitrate reductase use ATP?
The transmembrane nitrate reductase (NAR) does proton translocation and can contribute to the generation of ATP by the proton motive force. A transmembrane nitrate reductase that can function as a proton pump (similar to the case of anaerobic respiration) has been discovered in a diatom Thalassiosira weissflogii.
How is the nitrate reductase activity controlled?
In higher plants, nitrate reduction is highly regulated. A range of environmental factors influence the expression of the corresponding genes as well as the enzyme activity levels. NR activity expression and activity is controlled by light, temperature, pH, CO2, O2, water potential and N source.
What prosthetic group is nitrate reductase?
Nitrate reductase (NR) is a multi-domain enzyme comprising the prosthetic groups molybdopterin, Fe-heme, and FAD (flavin adenine dinucleotide) in a 1:1:1 stoichiometry that mediates an electron transfer from NAD(P)H to nitrate.