|Gene:||nirA||Accession Number: SYNPCC7942_1240 (MetaCyc)|
Species: Synechococcus elongatus PCC 7942
The gene encoding nitrite reductase from the cyanobacterium Synechococcus elongatus PCC 7942 has been identified and sequenced [Luque93]. This gene encodes a polypeptide that shows similarity to nitrite reductase from higher plants and to the sulfite reductase hemoprotein from enteric bacteria.
Identities with the above-mentioned proteins were found in the region that holds an Fe4S4-siroheme active center, suggesting that nitrite reductase from Synechococcus bears an active site similar to that present in those reductases.
Addition of ammonium abolished the accumulation of the transcript, indicating that ammonium is an inhibitor of transcription. L-glutamine, the immediate product of ammonium fixation, also showed negative effect on the transcription of cbbL, encoding the large subunbit of RubisCO. In addition, the glutamine metabolites cyanate and carbamoyl-phosphate were shown to repress transcription of nirA [Johnson].
|Map Position: [1,263,263 <- 1,264,801]|
Molecular Weight of Polypeptide: 56.541 kD (from nucleotide sequence)
Relationship Links: InterPro:IN-FAMILY:IPR005117 , InterPro:IN-FAMILY:IPR006066 , InterPro:IN-FAMILY:IPR006067 , InterPro:IN-FAMILY:IPR012798 , Pfam:IN-FAMILY:PF01077 , Pfam:IN-FAMILY:PF03460 , Prints:IN-FAMILY:PR00397 , Prosite:IN-FAMILY:PS00365
Enzymatic reaction of: ferredoxin--nitrite reductase
EC Number: 188.8.131.52
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
The reaction is favored in the opposite direction.
In Pathways: nitrate reduction VI (assimilatory)
Luque93: Luque I, Flores E, Herrero A (1993). "Nitrite reductase gene from Synechococcus sp. PCC 7942: homology between cyanobacterial and higher-plant nitrite reductases." Plant Mol Biol 21(6);1201-5. PMID: 8490140
Suzuki96: Suzuki I, Sugiyami T, Omata T (1996). "Regulation by cyanate of the genes involved in carbon and nitrogen assimilation in the cyanobacterium Synechococcus sp. strain PCC 7942." J Bacteriol 178(9);2688-94. PMID: 8626339
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