<p>The main stem loop of the inhibitory structure of <i>RPL22B</i>i was necessary but not sufficient for splicing inhibition.</p>

<p>The experiment was done and the figure was formatted as in <a href="plosone.org/article/info:doi/10.1371/journal.pone.0359197#pone.0359197.g002" target="_blank">Fig 2</a>. (A) The inhibitory mechanism required that specific structural details of the I structure remain intact. In the mutants analyzed in this set, the main stem loop is predicted to form.

Melting of Loop2 of the I structure (BPmut4; see panel (C)) renders the structure splicing permissive, while ablating the loop (dLoop2) retains the Rpl22-dependent inhibitory potential. Although the stability of the main stem loop should be lowered in Mutclamp2, it is apparently still sufficient to keep the I structure Rpl22 responsive. (B) Summary of the reporter experiments in (A) and types of stem loop arrangement predicted by RNAshapes. pre-mRNA accumulation was approximated on a scale of ‘+++’ to ‘-.’ The secondary structures were predicted using RNAshapes [<a href="plosone.org/article/info:doi/10.1371/journal.pone.0359197#pone.0359197.ref054" target="_blank">54</a>].