Solid-state NMR ¹³C, ¹⁵N assignments of human histone H3 in the nucleosome core particle

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.