Fig. 4. DNA-binding region of TOP1 in the open and closed conformations.

a Comparison of the relative positions of DNA interacting residues of CsTOP1 and HsTOP1. b Interaction between the lip2 and DNA interacting residues in the open state CsTOP1. CsTOP1 coloring is the same as in Fig. 1. c Position of the linker and DNA in the HsTOP1 crystal structure (PDB 1K4T)¹⁰ (right panel). For the left panel, the putative position of the DNA molecule interacting with CsTop1 is calculated after superposition using Pymol of CsTop1 structure with HsTOP1-DNA structure (PDB 1K4T). The basic residues are colored blue.