Structural basis for the recognition of CENP-A nucleosome by inner kinetochore protein CENP-N

Recognition of CENP-A-containing chromatin by CENP-N is a critical step in the assembly of functional kinetochore at the centromere to enable accurate chromosome segregation during cell division. The N-terminal domain of CENP-N binds CENP-A and its C-terminal domain interacts with CENP-L, which further associates with CENP-C and CENP-HIKM complex to promote kinetochore assembly. However, the structure of the N-terminal domain of CENP-N and the pattern of interaction between CENP-N and CENP-A nucleosome core particle (NCP) remain elusive, significantly limiting our understanding of CENP-N recognition of CENP-A NCP at kinetochores. Here we reported the cryo-EM structure at 5.8 Å resolution of CENP-A NCP/CENP-LN complex, which for the first time reveals the pattern of interaction between CENP-N and CENP-A NCP, as well as the molecular basis of how the N- and C-terminal domains of CENP-N pack together to bridge CENP-A NCP and CENP-L. The recognition of CENP-A NCP by CENP-N requires the interactions of CENP-N with CENP-A RG loop, histone H2B αC helix and nucleosomal DNA. Since CENP-A and CENP-L but not CENP-E stably associate with kinetochore in a CENP-N dependent manner, we reason that human kinetochores have evolved an elaborate kinetochore assembly machinery to ensure accurate chromosome segregation during cell division. Taken together, our study sheds lights on how CENP-N specifically recognizes CENP-A containing chromatin and recruits other components to orchestrate kinetochore assembly.

ADDITIONAL REFERENCES:

Cell Research Article: https://rdcu.be/4gGu

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