Figure 11
From: A functional type I topoisomerase from Pseudomonas aeruginosa
In the figure is shown the cleavage site assembly for the human topoisomerase (PDB IK4T) (panel A) and Vaccinia topoisomerase IB (PDB IA4I) (panel B). The human topoisomerase IB has a preassembled precleavage site but in the Vaccinia enzyme, the catalytic tyrosine is located away from the cleavage site and is reoriented after DNA binding.