sentences:  YkkC-yxkD leader
  
  The ykkC/yxkD leader is a conserved RNA structure found upstream of the ykkC and yxkD genes in "Bacillus subtilis" and related genes in other bacteria.The function of this family is unclear for many years although it has been suggested that it may function to switch on efflux pumps and detoxification systems in response to harmful environmental molecules.