title: Ndc10 is a platform for inner kinetochore assembly in budding yeast.
abstract: Kinetochores link centromeric DNA to spindle microtubules and ensure faithful chromosome segregation during mitosis. In point-centromere yeasts, the CBF3 complex Skp1-Ctf13-(Cep3)(2)-(Ndc10)(2) recognizes a conserved centromeric DNA element through contacts made by Cep3 and Ndc10. We describe here the five-domain organization of Kluyveromyces lactis Ndc10 and the structure at 2.8 Å resolution of domains I-II (residues 1-402) bound to DNA. The structure resembles tyrosine DNA recombinases, although it lacks both endonuclease and ligase activities. Structural and biochemical data demonstrate that each subunit of the Ndc10 dimer binds a separate fragment of DNA, suggesting that Ndc10 stabilizes a DNA loop at the centromere. We describe in vitro association experiments showing that specific domains of Ndc10 interact with each of the known inner-kinetochore proteins or protein complexes in budding yeast. We propose that Ndc10 provides a central platform for inner-kinetochore assembly.
authors.affiliation: Jack and Eileen Connors Structural Biology Laboratory and Howard Hughes Medical Institute, Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Uhn-Soo
authors.initials: US
authors.lastname: Cho
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Harrison
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D018360:Crystallography, X-Ray; D004271:DNA, Fungal / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D024202:Electrophoretic Mobility Shift Assay; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018386:Kinetochores / Q000378:metabolism*; D007716:Kluyveromyces / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
chemical_list: D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins