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Centromeres are present on each chromosome to direct proper segregation during cell division. The understanding of how the histone H3 variant, CENP-A, epigenetically marks the location of the centromere on the chromosome has been advanced, in part, through the study of histone complexes, nucleosomes, and nucleosomal complexes with nonhistone centromere proteins. In this chapter, we describe the preparation of recombinant versions of these complexes. The methodology is firmly rooted in classic nucleosome reconstitution methods, but we highlight the aspects of the preparations that diverge from those used for the methods established with canonical histones. We also provide a method for producing PCR-amplified nucleosomal DNA sequences in milligram quantities that is particularly useful for studies where multiple sequences and/or chemical modifications are desired. Lastly, we describe our approach to assemble and analyze a complex between the recombinant human CENP-A nucleosome and one of its binding partners, CENP-C., (© 2016 Elsevier Inc. All rights reserved.)

The key to understanding centromere identity is likely to lie in the chromatin containing the histone H3 variant CENP-A. CENP-A is the prime candidate to carry the epigenetic information that specifies the chromosomal location of the centromere in nearly all eukaryotic species, raising questions fundamental to understanding chromosome inheritance: How is the epigenetic centromere mark propagated? What physical properties of CENP-A-containing complexes are important for epigenetically marking centromeres? What are the molecules that recognize centromeric chromatin and serve as the foundation for the mitotic kinetochore? We discuss recent advances from our research groups that have yielded substantial insight into these questions and present our current understanding of the centromere. Future work promises an understanding of the molecular processes that confer fidelity to genome transmission at cell division.