The YdaO/YuaA leader (now called the cyclic di-AMPriboswitch) is a conserved RNA structure found upstream of the ydaO and yuaA genes in Bacillus subtilis and related genes in other bacteria. Its secondary structure and gene associations were predicted by bioinformatics.[1]
These RNAs function as riboswitches, and sense the signaling molecule cyclic di-AMP.[2] The interaction between the riboswitch and c-di-AMP has been revealed in atomic-resolution structures.[3][4][5]