Fig. 2: Conformational changes of the E5 helicase domains upon DNA and ATP binding.

Top view of the DNA-bound E5 complex (structure 1, a) and the E5 in the apo state (b). The bound DNA is shown in red surface in the DNA binding channel of E5. A red circle marks the collar region. The superimposition of the DNA-bound E5 complex with the E5 apo form, shown in top view (c) and side view (d). The blue arrows highlight the movement direction of the AAA+ domains and the WHD. Protomers A-F in the DNA-bound E5 are multicolored, while the apo E5 form is shown in gray. e, f Side view of E5-ssDNA-ATP complex (structure 1) and apo E5 (f), with the AAA+ domains are highlighted by a blue box and the collar region marked by a red rounded rectangle. The blue arrows highlight the movement direction of the AAA+ domains and the WHD. g The schematic model of the inward-upward-lateral movement between protomers after substrate incorporation of E5. The black dots and the colored dots represent the corresponding subunits of E5 in the apo state and in the DNA-bound state, respectively. The blue arrows highlight the movement of the AAA+ domain and the WHD. h Superimposition of protomers (A–F) in E5-ssDNA-ATP complex (structure 1), with the collar subunits fixed. Blue arrows indicate the lateral movement (left) and the inward and upward movement towards the ssDNA binding axis (right) of helicase domains after substrate incorporation. The transition motif is highlighted by a red dashed oval.