The seven nap genes at minute 47 on the Escherichia coli K-12 chromosome encode a functional nitrate reductase located in the periplasm. The molybdoprotein, NapA, is known to be essential for nitrate reduction. We now demonstrate that the two c-type cytochromes, the periplasmic NapB and the membrane-associated NapC, as well as a fourth polypeptide, NapD, are also essential for nitrate reduction in the periplasm by physiological substrates such as glycerol, formate and glucose. None of the three iron-sulphur proteins, NapF, NapG or NapH, are essential, irrespective of whether the bacteria are grown anaerobically in the presence of nitrate or fumarate as a terminal electron acceptor, or by glucose fermentation. Mutation of napD resulted in the total loss of Methyl Viologen-dependent nitrate reductase activity of the molybdoprotein, NapA, consistent with an earlier suggestion by others that NapD might be required for post-translational modification of NapA.
| Predicate | Object |
|---|---|
| rdf:type | |
| rdfs:comment |
The seven nap genes at minute 47 on the Escherichia coli K-12 chromosome encode a functional nitrate reductase located in the periplasm. The molybdoprotein, NapA, is known to be essential for nitrate reduction. We now demonstrate that the two c-type cytochromes, the periplasmic NapB and the membrane-associated NapC, as well as a fourth polypeptide, NapD, are also essential for nitrate reduction in the periplasm by physiological substrates such as glycerol, formate and glucose. None of the three iron-sulphur proteins, NapF, NapG or NapH, are essential, irrespective of whether the bacteria are grown anaerobically in the presence of nitrate or fumarate as a terminal electron acceptor, or by glucose fermentation. Mutation of napD resulted in the total loss of Methyl Viologen-dependent nitrate reductase activity of the molybdoprotein, NapA, consistent with an earlier suggestion by others that NapD might be required for post-translational modification of NapA.
|
| skos:exactMatch | |
| uniprot:name |
Biochem. J.
|
| uniprot:author |
Cole J.A.,
Potter L.C.
|
| uniprot:date |
1999
|
| uniprot:pages |
69-76
|
| uniprot:title |
Essential roles for the products of the napABCD genes, but not napFGH, in periplasmic nitrate reduction by Escherichia coli K-12.
|
| uniprot:volume |
344
|
| dc-term:identifier |
doi:10.1042/0264-6021:3440069
|