Structural mechanisms of centromeric nucleosome recognition by the kinetochore protein CENP-N

We report cryo–electron microscopy (cryo-EM), biophysical, biochemical, and cell biological studies of the interaction between the CENP-A nucleosome and CENP-N. We show that human CENP-N confers binding specificity through interactions with the L1 loop of CENP-A, stabilized by electrostatic interactions with the nucleosomal DNA. Mutational analyses demonstrate analogous interactions in Xenopus, which are further supported by residue-swapping experiments involving the L1 loop of CENP-A. Our results are consistent with the coevolution of CENP-N and CENP-A and establish the structural basis for recognition of the CENP-A nucleosome to enable kinetochore assembly and centromeric chromatin organization.

Source: ScienceNOW - January 18, 2018 Category: Science Authors: Chittori, S., Hong, J., Saunders, H., Feng, H., Ghirlando, R., Kelly, A. E., Bai, Y., Subramaniam, S. Tags: Biochemistry, Cell Biology reports Source Type: news