Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
Nucleus. 2012 Jan-Feb;3(1):6-11. doi: 10.4161/nucl.18372.
Centromeres are epigenetically marked by the assembly of nucleosomes containing the centromere-specific histone H3 variant, CENP-A (CENP-A nucleosome) and their inheritance is probably dictated by the architecture of the centromeric nucleosome. We previously determined the crystal structure of the human CENP-A nucleosome. CENP-A forms a histone octamer containing two each of histones H2A, H2B, H4 and CENP-A and the DNA is left-handedly wrapped around the histone octamer, as in canonical nucleosomes containing histone H3. In the CENP-A nucleosome structure, 13 base pairs of the DNA ends are detached from the histone surface and two CENP-A regions, the αN helix and loop 1, adopt different structures from those in the H3 nucleosome. In this Extra View article, we provide a detailed structural comparison between CENP-A and H3 in nucleosomes and describe their distinctions and similarities.
着丝粒通过组装含有着丝粒特异性组蛋白 H3 变体 CENP-A（CENP-A 核小体）的核小体在表观遗传上被标记，其遗传可能由着丝粒核小体的结构决定。我们之前确定了人源 CENP-A 核小体的晶体结构。CENP-A 形成一个包含两个 H2A、H2B、H4 和 CENP-A 的组蛋白八聚体，DNA 以左手方式缠绕在组蛋白八聚体上，就像含有组蛋白 H3 的典型核小体一样。在 CENP-A 核小体结构中，DNA 的 13 个碱基对从组蛋白表面脱离，并且 CENP-A 的两个区域，αN 螺旋和环 1，采用与 H3 核小体不同的结构。在这篇额外视图文章中，我们提供了 CENP-A 与核小体中 H3 之间的详细结构比较，并描述了它们的区别和相似之处。
