In the present study, the influence of a series of aminated molecules
or metabolites on the activity of the CChMVd-HHR was investigated.
Among them adenine was tested since this molecule appeared to bind
to RNAs and modulate their activities. This is the case of the adeninedependent
hairpin ribozyme [20] and of the adenine riboswitch [21].
Interestingly, HHR and the adenine riboswitch present structural and
mechanistic similarities. They fold into a very similar secondary structure
formed by a central core, three stems and two loops and they are
activated through the same loop–loop interactions ([15,16] for HHR
and [22] for the adenine riboswitch).