Figure 8. Model of the physical basis for the stability of CENP-A nucleosomes within the CCNC.

See text for the details of our model of centromere maintenance. We note that CENP-C^CD is shown as an elongated oval that represents a structured loop that has no conventional secondary structure, despite having been historically called a ‘domain'. Also, a flexible linker is shown between CENP-C^CD and the CENP-C contact point with the CENP-L-N complex, in line with proposals that CENP-C largely exists as an extended and unfolded protein that may span >100 nm at mitotic kinetochores⁶⁵,⁶⁶,⁶⁷. In addition, it is also not known if there is a fixed or variable distance at centromeres from the CENP-C-L-N contact point to the CENP-A nucleosome. It is also unclear if this contact point on CENP-C with CENP-L-N is a folded domain or if it contacts one or both subunits of CENP-L-N.