Insights into Centromere DNA Bending Revealed by the Cryo-EM Structure of the Core Centromere Binding Factor 3 with Ndc10

Abstract

Summary: The centromere binding factor 3 (CBF3) complex binds the third centromere DNA element in organisms with point centromeres, such as S. cerevisiae. It is an essential complex for assembly of the kinetochore in these organisms, as it facilitates genetic centromere specification and allows association of all other kinetochore components. We determined high-resolution structures of the core complex of CBF3 alone and in association with a monomeric construct of Ndc10, using cryoelectron microscopy (cryo-EM). We identify the DNA-binding site of the complex and present a model in which CBF3 induces a tight bend in centromeric DNA, thus facilitating assembly of the centromeric nucleosome. : Zhang et al. determine two cryo-EM structures of the budding yeast centromere binding factor CBF3. These structures show that CBF3 must bend the centromere DNA element CDEIII, and this may promote looping of the centromere to accommodate a centromeric nucleosome. Keywords: point centromere, kinetochore, CBF3, cryo-EM, Ndc10