"Toroidal processive enzymes (e.g. enzymes/proteins that are able to thread onto biopolymers and to perform stepwise reactions along the polymer chain) are among the most fascinating tools involved in the clockwork machinery of life. Processive catalysis is ubiquitous in Nature, viz. DNA polymerases, endo- and exo-nucleases and; it plays a crucial role in numerous events of the cell’s life, includ ...