Cyano S1 RNA motif

The Cyano-S1 RNA motif (originally named the Cyano-30S motif) is a conserved RNA structure present in some species of Cyanobacteria. Cyano-S1 RNAs are consistently found upstream of genes encoding ribosomal protein S1, a subunit of the ribosome. Therefore, they are presumed to be ribosomal protein leaders, i.e., cis-regulatory elements to which the ribosomal protein S1 binds, thereby controlling its expression levels.