Nucleosome core particle (NCP), the basic unit of chromatin in eukaryotic cells, consists of ~ 147 bp DNA wrapped around a histone octamer (HO) formed by two H2A–H2B dimers and one (H3–H4)₂ tetramer. Histones undergo various post-translational modifications (PTMs), which regulates genomic activities in different cellular phases. High-resolution structures have been solved for many nucleosomes primarily including NCPs. However, the atomic-resolution structures of nucleosome arrays and chromatin fiber, as well as the dynamics of nucleosomes remain poorly understood. Solid-state NMR (SSNMR) is one of the premier techniques to answer these questions. In this study, we present the ¹³C and ¹⁵N chemical shifts assignments for the globular domain of human histone H3 (hH3) using multidimensional SSNMR experiments. The obtained spectra are of outstanding resolution and the assignments are nearly 100% complete for the backbone ¹³C and ¹⁵N spins of R42–G132 and ~ 80% when taking into account the side chains. The secondary structure derived from the chemical shifts agrees with the previously reported X-ray crystal structure. The reported chemical shifts can be carried over to future SSNMR studies of structure and dynamics of hH3 in NCPs, nucleosome array, chromatin fibers and nucleosome-protein complexes.

中文翻译：

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核糖体核心颗粒中人组蛋白H3的固态NMR 13 C，15 N赋值

核小体核心颗粒（NCP）是真核细胞中染色质的基本单位，由〜147 bp DNA包裹，该DNA包裹着由两个H2A–H2B二聚体和一个（H3–H4）₂四聚体形成的组蛋白八聚体（HO）。组蛋白经过各种翻译后修饰（PTM），可调节不同细胞期的基因组活性。高分辨率结构已解决了许多主要包括NCP的核小体的问题。然而，对核小体阵列和染色质纤维的原子分辨率结构以及核小体的动力学仍然知之甚少。固态NMR（SSNMR）是回答这些问题的主要技术之一。在这项研究中，我们介绍了 ¹³ C和¹⁵使用多维SSNMR实验，人组蛋白H3（hH3）球状结构域的N个化学位移分配。获得的光谱具有出色的分辨率，并且对于R42–G132的主链¹³ C和¹⁵ N自旋，分配几乎是100％完整的；考虑到侧链，分配则约为80％。由化学位移产生的二级结构与先前报道的X射线晶体结构一致。所报道的化学位移可用于将来的NHC，核小体阵列，染色质纤维和核小体-蛋白质复合物中hH3的结构和动力学的SSNMR研究。