The twister ribozyme’s self-cleavage mechanism is hypothesized to use substrate-assisted catalysis. RNA hexamer models were designed from those detailed in a previous paper whereby RNA hexamers engaged in specific self-cleavage around CA and UA motifs. Experimental results and a recent study discussing Tudor SN that cleaves about these motifs indicates that these linkages may possess no intrinsic reactivity.  We conclude that the full twister active site is needed for any detectable level of specific cleavage.