NsiR4 (nitrogen stress-induced RNA 4), former name SyR12, is a cyanobacterial non-coding RNA which plays role in the regulation of

Glutamine synthetase Glutamine synthetase (GS) () is an enzyme that plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate and ammonia to form glutamine: Glutamate + ATP + NH3 → Glutamine + ADP + phosphate Glutam ...

(GS), a key enzyme in biological

nitrogen assimilation Nitrogen assimilation is the formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds present in the environment. Organisms like plants, fungi and certain bacteria that can fix nitrogen gas (N2) depend on the abil ...

. NsiR4 interacts with the 5′UTR of the mRNA of the GS inactivating factor IF7 (''gifA'' mRNA) and reduces its expression. NsiR4 expression is under positive control of the nitrogen control transcription factor (NtcA). NsR4 is a first example of an sRNA controlling the assimilation of a micronutrient.

References

RNA Non-coding RNA {{molecular-cell-biology-stub