Left: cylinder representation of the APC/C-Nek2A complex structure. Apc2 (light blue) and Apc4 (light brown) are highlighted, the rest of the APC/C is shown in transparency. (i) Two different views of cryo-EM density for the Apc2 and Apc4 subunits. Secondary structure elements of the Apc2WHB domain are highlighted. (ii) Cryo-EM density for the second MR tail of Nek2A.   Details of the second MR tail binding site formed by the Apc2 (including the repositioned Apc2WHB) and Apc4 subunits. Nek2AMR2 is shown in orange.   