Subunit interactions and arrangements in the fission yeast Mis16-Mis18-Mis19 complex.

Centromeric chromatin in fission yeast is distinguished by the presence of nucleosomes containing the histone H3 variant Cnp1CENP-A Cell cycle-specific deposition of Cnp1 requires the Mis16-Mis18-Mis19 complex, which is thought to direct recruitment of Scm3-chaperoned Cnp1/histone H4 dimers to DNA. Here, we present the structure of the essential Mis18 partner protein Mis19 and describe its interaction with Mis16, revealing a bipartite-binding site. We provide data on the stoichiometry and overall architecture of the complex and provide detailed insights into the Mis18-Mis19 interface.