EC Number | Protein Variants | Comment | Organism |
---|---|---|---|
1.7.7.2 | additional information | construction of A narB knockout mutant using a homologous recombination strategy. The DnarB strain produces 7times more H2 than the wild-type after 2 days of fermentation, while in the absence of nitrate, both DELTAnarB and wild-type produce the same amount of H2, as expected. The DELTAnarB strain cannot grow photoautotrophically on nitrate, but does grow on urea or ammonia. The DELTAnarB strain significantly redirects biomass accumulation into glycogen reserves at the expense of protein accumulation throughout growth. Phenotype, overview | Synechococcus sp. PCC 7002 |
EC Number | Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|---|
1.7.7.2 | nitrate + 2 reduced ferredoxin + 2 H+ | Synechococcus sp. PCC 7002 | - |
nitrite + H2O + 2 oxidized ferredoxin | - |
? |
EC Number | Organism | UniProt | Comment | Textmining |
---|---|---|---|---|
1.7.7.2 | Synechococcus sp. PCC 7002 | Q9R6U4 | - |
- |
EC Number | Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|---|
1.7.7.2 | nitrate + 2 reduced ferredoxin + 2 H+ | - |
Synechococcus sp. PCC 7002 | nitrite + H2O + 2 oxidized ferredoxin | - |
? |
EC Number | Synonyms | Comment | Organism |
---|---|---|---|
1.7.7.2 | narB | - |
Synechococcus sp. PCC 7002 |
1.7.7.2 | nitrate reductase | - |
Synechococcus sp. PCC 7002 |
EC Number | Cofactor | Comment | Organism | Structure |
---|---|---|---|---|
1.7.7.2 | Ferredoxin | - |
Synechococcus sp. PCC 7002 |
EC Number | General Information | Comment | Organism |
---|---|---|---|
1.7.7.2 | malfunction | the narB knockout of Synechococcus sp. 7002 is sufficient to redirect the dominant flux of electrons from nitrate reduction to other fermentative metabolites, including a 6fold higher H2 yield than in the wild-type strain. The DELTAnarB mutant is able to take up intracellular nitrate but is unable to reduce it to nitrite or ammonia, and is unable to grow photoautotrophically on nitrate. During photoautotrophic growth on urea, mutant DELTAnarB significantly redirects biomass accumulation into glycogen at the expense of protein accumulation. Because there is no metabolism of nitrate in the DELTAnarB strain, nitrate cannot act as a strong terminal electron acceptor to lower the cellular redox poise, which is known to inhibit glucose-6-phosphate dehydrogenase (G6PDH) activity. Phenotype, overview | Synechococcus sp. PCC 7002 |
1.7.7.2 | physiological function | once nitrate is transported into the cell by nitrate permease (NrtP), two reduced ferredoxin molecules reduce one nitrate to one nitrite, catalyzed by nitrate reductase (encoded by gene narB) | Synechococcus sp. PCC 7002 |