[1] SAM-V features a similar consensus sequence and secondary structure as the binding site of SAM-II riboswitch, but bioinformatics scans cluster the two aptamers independently.

These similar binding pockets suggest that the two riboswitches have undergone convergent evolution.

When SAM is present in high concentration, SAM-II will bind its ligand and form a terminator stem to halt transcription.

This regulation controls parts of the sulfur metabolism of marine bacteria.

[2] The crystal structure of the riboswitch has been solved (PDB 6FZ0).