Figure 2.

Schematic summary of the structural organization of budding yeast and human kinetochores. Related colors highlight conserved components/complexes. (A) Schematic of the S. cerevisiae kinetochore with subunit names; (B) The S. cerevisiae centromere (CEN) DNA is stereotyped and contains CDEI, CDEII, and CDEIII regions, which bind CBF1, Cse4^CENP-A, and CBF3, respectively; (C) Folding of CEN DNA around a Cse4 nucleosome brings CBF1 and CBF3 in close proximity; (D) Schematic of the H. sapiens kinetochore. Orthologous complexes are shown in the same order as in (A); (E) The unit of human centromere assembly may consist of a pair of α-satellite repeats, each precisely wrapping around a nucleosome. One of the two α-satellite repeats carries a CENP-B box. The CENP-TW complex may interact in the inter-nucleosomal region through its histone-fold domain (HFDs) [77,78]. Repeats of this unit give rise to α-satellite arrays, which in turn may organize themselves in higher order repeats (HORs); (F) The human centromere arises from folding of centromeric chromatin in three dimensions to facilitate the participation of several CENP-A nucleosomes in kinetochore assembly.