Panel A shows a composite structural model of the full S. cerevisiae K M N complex, integrating N d c 80 c, K n l 1 c, and M i s 12 c M t w 1 c, highlighting coiled-coil regions, calponin homology (C H) domains, linker regions, and subunit organization. Panel B shows an A F 2-predicted structure of the Knl1:Mis12cMtw1c assembly, highlighting the Knl1c helical bundle, RWD domains, linker regions, and interactions with the Mis12cMtw1c stalk (CC3), with accompanying pLDDT coloring and PAE plot. Panel C shows an A F 2-predicted model of Ndc80 colored by pL D D T confidence, with an inset PAE map indicating model reliability.
Hypothetical model of the entire S. cerevisiae KMN complex and comparison with humans. (A) Model of the entire S. cerevisiae KMN complex based on the structures determined experimentally in this study and AF2 models of Knl1c and Ndc80c. Flexibility of Ndc80c has been demonstrated (Scarborough et al., 2019; Wang et al., 2008), and flexibility of the Knl1c helical bundle is inferred from AF2 models. CH: calponin homology. N-tail: N-terminal tail. (B) AF2 structure prediction of Knl1c:Mis12cMtw1c showing the Knl1c helical bundle domain, Knl1c RWD domains, and Mis12cMtw1c stalk CC3 region. The structure was predicted using full-length, wild-type protein sequences colored by the residue pLDDT score with the PAE score plot shown above. PAE, predicted alignment error. (C) AF2 structure prediction of Ndc80c, colored by residue pLDDT score. The structure was predicted using full-length, wild-type protein sequences. The PAE score plot of the AF2 Ndc80c model is shown on the left of the panel.