[1] The Thermoanaerobacter tengcongensis sequence AE013027 overlaps with that of purine riboswitch suggesting that the two riboswitches may work in conjunction to regulate the upstream gene which codes for TTE0584 (Q8RC62), a member of the permease family.

Furthermore, they demonstrated that bacteria are capable of endogenously producing guanidine and the riboswitch controls genes whose products are involved in modification or pumping out guanidine as a toxic compound from bacteria.

However, the mini-ykkC RNA motif is simpler in structure and has fewer highly conserved nucleotide positions than the ykkC-yxkD leader.

Therefore, mini-ykkC RNA motif represents a distinct class of guanidine-sensing RNAs called Guanidine-II riboswitch.

The ykkC-III motif has a rigidly conserved ACGA sequence within it that resembles a less rigidly conserved ACGA or ACGG sequence found in mini-ykkC RNAs, but it is unknown whether this observation relates to a biological relationship.