Figure 4.

Katanin forms an asymmetric hexamer with a spiral arrangement of the AAA domains. Orthogonal views of the molecular surface of the assembled katanin hexamer in the spiral conformation showing the central AAA ring with radiating arms composed of a poorly conserved flexible linker and an N-terminal MIT domain. The AAA ring structure was determined by single-particle cryo-EM to 4.4 Å (PDB ID 5WC0; Zehr et al., 2017); the MIT domain structure was determined by NMR (PDB ID 2RPA; Iwaya et al., 2010); the structure of the flexible linker (gray) has not been experimentally determined and was modeled to have an approximate span as the one reported from small angle x-ray scattering (Zehr et al., 2017). Protomer P1, green; P2, cyan; P3, blue; P4, orange; P5, purple; and P6, red.