Like the other SAM riboswitch, it probably functions to turn off expression of these genes in response to elevated SAM levels. A significant variant of SAM-II riboswitches was found in Pelagibacter ubique and related marine bacteria and called SAM-V.  Also, like many structured RNAs, SAM-II riboswitches can tolerate long loops between their stems.
This SAM riboswitch likely plays a role in regulating gene expression when SAM levels are elevated. A significant example of a SAM-II riboswitch variant was found in Pelagibacter ubique and related marine bacteria, designated as SAM-V. Additionally, similar to other structured RNAs, SAM-II riboswitches can accommodate extended stem-loops that allow for flexibility.