9S53
Cryo-EM structure of the base of the Saccharomyces cerevisiae KMN junction complex containing the Mis12c(Mtw1c) head 2 domain
This is a non-PDB format compatible entry.
Summary for 9S53
| Entry DOI | 10.2210/pdb9s53/pdb |
| EMDB information | 54586 |
| Descriptor | Kinetochore-associated protein DSN1, Kinetochore-associated protein MTW1, Kinetochore-associated protein NNF1, ... (4 entities in total) |
| Functional Keywords | kinetochore, chromosome segregation, mitosis, cell cycle |
| Biological source | Saccharomyces cerevisiae S288C More |
| Total number of polymer chains | 4 |
| Total formula weight | 148185.14 |
| Authors | Turner, N.N.,Barford, D. (deposition date: 2025-07-29, release date: 2026-04-08, Last modification date: 2026-04-22) |
| Primary citation | Turner, N.N.,Zhang, Z.,Yang, J.,Muir, K.W.,McLaughlin, S.H.,Morgan, T.,Barford, D. Assembly and phosphoregulatory mechanisms of the budding yeast outer kinetochore KMN complex. J.Cell Biol., 225:-, 2026 Cited by PubMed Abstract: During mitosis and meiosis, kinetochores mediate interactions between chromosomes and spindle microtubules. Kinetochores are multi-megadalton protein complexes essential for chromosome segregation; however, recent structural, functional, and evolutionary studies have revealed divergent mechanisms of kinetochore assembly. Here, we use cryo-EM to understand the structural mechanisms by which the budding yeast microtubule-binding outer kinetochore KMN complex assembles, and how its interactions with the centromere-binding inner kinetochore are regulated. The KMN complex comprises three subcomplexes: Knl1c, Mis12cMtw1c, and Ndc80c. We show how C-terminal motifs of the Mis12cMtw1c subunits Dsn1, Mis12Mtw1, and Nnf1 bind Knl1c and Ndc80c. At the opposite end of the Mis12cMtw1c stalk, an N-terminal auto-inhibitory segment of Dsn1 (Dsn1AI) folds into two α-helices that engage the Mis12cMtw1c head 1 domain, thereby occluding binding sites for the inner kinetochore subunits CENP-CMif2 and CENP-UAme1, reducing their affinity for Mis12cMtw1. Our structure reveals how Aurora BIpl1 phosphorylation of Dsn1AI would release this auto-inhibition to substantially strengthen preexisting connections between the inner and outer kinetochore. PubMed: 41956986DOI: 10.1083/jcb.202506015 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (6.5 Å) |
Structure validation
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