Tachiwana Hiroaki, Kurumizaka Hitoshi
Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan.
Genes Genet Syst. 2011;86(6):357-64. doi: 10.1266/ggs.86.357.
Centromeres are dictated by the epigenetic inheritance of the centromeric nucleosome containing the centromere-specific histone H3 variant, CENP-A. The structure of the CENP-A nucleosome has been considered to be the fundamental architecture of the centromeric chromatin. Controversy exists in the literature regarding the CENP-A nucleosome structures, with octasome, hemisome, compact octasome, hexasome, and tetrasome models being reported. Some of these CENP-A nucleosome models may correspond to transient intermediates for the assembly of the mature CENP-A nucleosome; however, their significances are still unclear. Therefore, the structure of the mature CENP-A nucleosome has been eagerly awaited. We reconstituted the human CENP-A nucleosome with its cognate centromeric DNA fragment, and determined its crystal structure. In this review, we describe the structure and the physical properties of the CENP-A nucleosome, and discuss their implications for centromeric chromatin architecture.
着丝粒由包含着丝粒特异性组蛋白H3变体CENP-A的着丝粒核小体的表观遗传继承所决定。CENP-A核小体的结构被认为是着丝粒染色质的基本结构。关于CENP-A核小体结构，文献中存在争议，已报道了八聚体、半体、紧密八聚体、六聚体和四聚体模型。这些CENP-A核小体模型中的一些可能对应于成熟CENP-A核小体组装的瞬时中间体；然而，它们的意义仍不清楚。因此，人们一直急切地期待着成熟CENP-A核小体的结构。我们用其同源着丝粒DNA片段重建了人类CENP-A核小体，并确定了其晶体结构。在这篇综述中，我们描述了CENP-A核小体的结构和物理性质，并讨论了它们对着丝粒染色质结构的影响。
