a, Core kinetochore proteins co-purify with Dsn1-FLAG as visualized by silver-stained SDS-PAGE. Asterisk indicates non-specific co-purifying proteins. b, Immunoblot confirms co-association of DNA- and microtubule-binding components with Dsn1-FLAG. c, Mass spectrometry identifies all components of kinetochore subcomplexes except CBF3. Identities, percent sequence coverage, and number of identified peptides of core kinetochore proteins are shown. See Table S1 for all proteins identified by mass spectrometry. d, Eluted kinetochore particles were subjected to S-500 size exclusion chromatography and analyzed by immunoblots. The kinetochore proteins analyzed co-migrate as a complex (Stokes radius ~25 nm). Fig. S3 shows additional fractions.