ジャーナル: Mol Cell / 年: 2022 タイトル: Structure of the human inner kinetochore CCAN complex and its significance for human centromere organization. 著者: Marion E Pesenti / Tobias Raisch / Duccio Conti / Kai Walstein / Ingrid Hoffmann / Dorothee Vogt / Daniel Prumbaum / Ingrid R Vetter / Stefan Raunser / Andrea Musacchio / 要旨: Centromeres are specialized chromosome loci that seed the kinetochore, a large protein complex that effects chromosome segregation. A 16-subunit complex, the constitutive centromere associated ...Centromeres are specialized chromosome loci that seed the kinetochore, a large protein complex that effects chromosome segregation. A 16-subunit complex, the constitutive centromere associated network (CCAN), connects between the specialized centromeric chromatin, marked by the histone H3 variant CENP-A, and the spindle-binding moiety of the kinetochore. Here, we report a cryo-electron microscopy structure of human CCAN. We highlight unique features such as the pseudo GTPase CENP-M and report how a crucial CENP-C motif binds the CENP-LN complex. The CCAN structure has implications for the mechanism of specific recognition of the CENP-A nucleosome. A model consistent with our structure depicts the CENP-C-bound nucleosome as connected to the CCAN through extended, flexible regions of CENP-C. An alternative model identifies both CENP-C and CENP-N as specificity determinants but requires CENP-N to bind CENP-A in a mode distinct from the classical nucleosome octamer.
凍結剤: ETHANE / チャンバー内湿度: 100 % / チャンバー内温度: 286 K / 装置: FEI VITROBOT MARK IV
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電子顕微鏡法
顕微鏡
FEI TITAN KRIOS
特殊光学系
位相板: VOLTA PHASE PLATE / 球面収差補正装置: Krios with CS corrector / エネルギーフィルター - 名称: GIF Bioquantum / エネルギーフィルター - スリット幅: 14 eV
撮影
フィルム・検出器のモデル: GATAN K3 (6k x 4k) / 平均電子線量: 55.8 e/Å2 詳細: 2678 images were collected in movie-mode with 60 frames per image on Gatan K3 in superresolution mode with 0.34 A pixel size / native pixel size 0.68A
電子線
加速電圧: 300 kV / 電子線源: FIELD EMISSION GUN
電子光学系
照射モード: OTHER / 撮影モード: BRIGHT FIELD / 最大 デフォーカス(公称値): 1.2 µm / 最小 デフォーカス(公称値): 0.6 µm / 倍率(公称値): 105000