Part : BBa_K896004

In Pseudomonas aeruginosa PAO1, NorCB is found as two sub-units – nitric oxide reductase subunit C and B. As a matter of fact, these two subunits are adjacent genes. And thus we cloned them together to produce a functional reductase.

NosZ is the structure gene of nitrous reductase. Very few microorganisms process similar enzyme, and many of them are homologs according to NCBI database. Furthermore, it performs the last procedure of bio-denitrification – nitrous oxides to nitrogen – in our model.

Obviously, the reason we cloned NorCB and NosZ on the same plasmid is to connect the continuous denitrifying procedures together.


Nitrite reductase is composed of several different subunits. Together, it can reduce nitrite to nitric oxide. We clone all these subunits together on the same plasmid in order to grant cyanobacteria a functional protein.


Nap( Nitrate->Nitrite reductase)
Nap is periplasmic nitrate reductase, which is known for the ability to reduce nitrate into nitrite. In microorganisms, similar reductases are often observed. For instance, even E. coli has its own nitrate reductase and can use nitrate as final electron acceptor. Moreover, we acquire the Nap gene from Desulfovibrio desulfuricans ATCC 27774.

Since Nir and Nap complex together would link the reducing reaction from Nitrate to nitric oxide, we ligated these two gene together and expressed them on Synechococcus elongatus PCC 7942.