4/8 Cryo-EM shows TranC (LaTranC) protein is structurally similar to its TnpB ancestor. The key innovation was at the RNA level: the guide reRNA functionally split into a tracrRNA & crRNA. Computional analysis indicate it as a convergent event across TranC clades.

3/8 These TranCs (e.g., LaTranC) are true intermediates: they can be guided by both CRISPR crRNAs AND transposon-derived reRNAs! This dual-guide capacity shows they retain ancestral TnpB function while acquiring CRISPR immunity.

2/8 Phylogenetic mining revealed several young Cas12 clades we call “TranCs”, i.e., nascent CRISPR systems emerging from distinct TnpB lineages. These represent multiple independent domestication events from transposons.