It is also found in DNA extracted from uncultivated bacteria living in the ocean that are presumably species of cyanobacteria.

glnA RNAs are found in the presumed 5' untranslated regions of genes encoding multiple classes of protein that are involved in nitrogen metabolism.

[1][2] It was demonstrated that glnA RNAs correspond to glutamine-binding riboswitches,[3] i.e., they sense glutamine concentrations in order to measure overall nitrogen availability, and regulate the downstream genes appropriately.

The original proposal of a riboswitch function was based on the above evidence that glnA RNAs are cis-regulatory, as well as the moderate structural complexity in the three-stem junction of the glnA RNA motif that is comparable to the structures of other known riboswitches.

The fact that RNAs from both motifs selectively bind glutamine supports this hypothesis, but detailed structural data is not yet available.