Extended Data Fig. 5: Cryo-EM densities of CCAN and CCAN–Cenp-ANuc complexes.
From: Structure of the inner kinetochore CCAN complex assembled onto a centromeric nucleosome
a, Cryo-EM reconstruction of CCAN–Cenp-ANuc from uncrosslinked sample at 8.6 Å resolution. b, Cryo-EM map of dimeric CCAN (also Extended Data Fig. 3a, black box). Subunits are colour-coded as in Fig. 1. The 3.5 Å monomeric free CCAN coordinates were rigid-body-docked into the cryo-EM map. c, Cartoon representation of the S. cerevisiae MIND complex15 (right), showing a notable similarity to the coiled coils of Cenp-QU–Nkp1–Nkp2 of CENP-OPQU+ (left). d, View of the 4.7 Å resolution cryo-EM map of free Cenp-HIK with fitted coordinates from CCAN. e, In the context of CCAN, Cenp-HIKHead rotates to accommodate Cenp-ANuc. The two conformations of Cenp-HIK from the apo-CCAN and CCAN–Cenp-ANuc complexes were superimposed onto their rigid portion of Cenp-HIK (C-terminal region of Cenp-I is shown for apo-CCAN) to indicate the conformational variability of Cenp-HIKHead between the two states. Subunits of Cenp-HIKHead of CCAN–Cenp-ANuc are coloured lighter. f, Cryo-EM density of Cenp-ANuc showing the Cenp-C motif of Cenp-C.
