Fig. 5: Comparison of TnpB with Cas12f and Cas12m.
From: Cryo-EM structure of the transposon-associated TnpB enzyme
Structural comparison of TnpB with Cas12f (Cas12f from an uncultured archaeon) (PDB ID: 7C7L) and Cas12m (Cas12m from Mycobacterium mucogenicum) (PDB ID: 8HHL). Cas12f and Cas12m share high sequence similarity with TnpB proteins. Cas12f mol.2- and Cas12m-specific insertions (REC2) are highlighted in blue. These regions have a crucial role for the recognition of the PAM-distal region of the guide RNA–target DNA heteroduplex, suggesting that type V Cas12 enzymes acquired an ability to recognize the PAM-distal end of the guide RNA–target DNA heteroduplex in order to engage in CRISPR–Cas adaptive immunity. ZF, zinc-finger ___domain.
