Complex interplay of riboregulatory mechanisms at the <i>gcvT</i> -NGFG_01513- <i>gcvH</i> operon of <i>Neisseria gonorrhoeae</i>

In the bacterial world, riboregulation is extremely widespread and controls virtually all aspects of the life of bacterial cells. Riboregulatory mechanisms are very diverse and involve <i>trans</i>- and <i>cis</i>-acting regulatory elements such as small RNAs and riboswitches that are able to control gene expression by direct binding of small molecules. Here, we report a very peculiar and rare example of riboregulation in which an mRNA is regulated by both <i>trans</i>-acting sibling sRNAs and a glycine-responsive tandem riboswitch, which control glycine metabolism of the human pathogen <i>Neisseria gonorrhoeae</i>. This regulatory interplay of sibling sRNAs with a tandem riboswitch allows integration of different cellular signals and represents an intriguing new facet of riboregulation.