Non-nucleosomal (CENP-A/H4)2 - DNA complexes as a possible platform for centromere organization.
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Ali-Ahmad A, Mors M, Carrer M, Li X, Bilokapić S, Halić M, Cascella M, Sekulić N
bioRxiv - (-) - [2025-01-01; online 2025-01-01]
The centromere is a part of the chromosome that is essential for the even segregation of duplicated chromosomes during cell division. It is epigenetically defined by the presence of the histone H3 variant CENP-A. CENP-A associates specifically with a group of 16 proteins that form the centromere-associated network of proteins (CCAN). In mitosis, the kinetochore forms on the CCAN to connect the duplicated chromosomes to the microtubules protruding from the cell poles. Previous studies have shown that CENP-A replaces H3 in nucleosomes, and recently the structures of CENP-A-containing nucleosomes in complex with CCANs have been revealed, but they show only a limited interaction between CCANs and CENP-A. Here, we report the cryoEM structure of 2x(CENP-A/H4)2-di-tetramers assembled on DNA in the absence of H2A/H2B histone dimer and speculate how (CENP-A/H4)2-tetramers and -di-tetramers might serve as a platform for CCAN organization.
PubMed 39803555
DOI 10.1101/2024.12.31.630874
Crossref 10.1101/2024.12.31.630874
pmc: PMC11722257
pii: 2024.12.31.630874