YybP-ykoY leader

The yybP-ykoY leader RNA element was originally discovered in E. coli during a large scale screen and was named SraF. This family was later found to exist upstream of related families of protein genes in many bacteria, including the the yybP and ykoY genes in B. subtilis. The specific functions of these proteins are unknown, but this structured RNA element may be involved in their genetic regulation as a riboswitch.