Merchán F, Kindle K L, Llama M J, Serra J L, Fernández E
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad del País Vasco, Bilbao, Spain.
Plant Mol Biol. 1995 Jul;28(4):759-66. doi: 10.1007/BF00021199.
A genomic region from the filamentous, thermophilic non-N2-fixing cyanobacterium Phormidium laminosum was cloned and sequenced. It includes the nitrite reductase gene (nirA) and three other genes (nrtA, B and C) located downstream of nirA, which are related to the nitrate transport system on the basis of a comparison with the homologous system from Synechococcus sp. PCC 7942. No additional nitrate assimilation-related genes were identified in about 5 kb sequenced downstream of nrtC. All four genes are arranged as an operon with a promoter-like region upstream of the nirA gene. Transcripts of these nitrate assimilation genes accumulated after long periods of nitrogen starvation. This operon also contains inverted repeat sequences in the intercistronic regions which might be involved in mRNA processing or stability.
对丝状嗜热非固氮蓝细菌层状席藻的一个基因组区域进行了克隆和测序。它包括亚硝酸还原酶基因（nirA）以及位于nirA下游的其他三个基因（nrtA、B和C），基于与聚球藻属PCC 7942同源系统的比较，这三个基因与硝酸盐转运系统相关。在nrtC下游约5 kb的测序区域中未发现其他与硝酸盐同化相关的基因。所有四个基因排列成一个操纵子，在nirA基因上游有一个类似启动子的区域。这些硝酸盐同化基因的转录本在长期氮饥饿后积累。这个操纵子在基因间区域还包含反向重复序列，可能参与mRNA的加工或稳定性调控。
