Supplementary Table 3 Strains used in this study.

Proteins were tagged at the C-terminus with EGFP, RFP or FRET probe through use of PCR cassettes unless otherwise noted. All Ndc80-FRET and Nuf2-FRET were expressed by using endogenous Ndc80 or Nuf2 promoter to maintain same protein expression level (see Supplementary Figs 1 and 5, and Methods).