Fig. 4: Global and local conformational changes induced by DNA binding.

a The subdomain reorganization of AsfvTop2 is illustrated by aligning EDI-1 (gray) with apo-IIa (pink). b Half model of a, with a 90° rotation around the x-axis. The black rectangle highlights the extended loop that appears upon DNA binding. c The extended loop (residues 481-493, colored in green) shown inside the black square in panel b. The corresponding region in yeast/human Top2^64,66 is colored in orange/blue, respectively. d The close-up stereo view of the specific interactions between AsfvTop2 and DNA in the square box in (c). The interactions are governed by the K479 and K480 of AsfvTop2, which are replaced with Glu and Ala (residue numbers in parentheses), respectively, in yeast/human Top2. e Upper panels: A global view of the local movements upon DNA binding with focus on the ß-HP1 region (left) and the catalytic Y800 (right). Lower panels: The enlarged view of the squared regions in the upper panel. Left: The three ß-HP loops from apo-IIa concurrently shift downward in the EDI-1 complex. Middle: The hydrophobic network that coordinates the concurrent movements of the three ß-HPs and α22 in the EDI-1 complex. Right: Shifting of the catalytic Y800 toward DNA in the complex. f Stereo view for the spatial locations of the three ß-HPs and Y800 in apo-Ia (colored in green with italic label), apo-IIa (colored in pink with underlined label), and the EDI-1 complex (gray).