Structure of the yeast nucleosome core particle reveals fundamental changes in internucleosome interactions

Abstract

Chromatin is composed of nucleosomes, the universally repeating protein±DNA complex in eukaryotic cells. The crystal structure of the nucleosome core particle from Saccharomyces cerevisiae reveals that the structure and function of this fundamental complex is conserved between single-cell organisms and metazoans. Our results show that yeast nucleosomes are likely to be subtly destabilized as compared with nucleosomes from higher eukaryotes, consistent with the idea that much of the yeast genome remains constitutively open during much of its life cycle. Importantly, minor sequence variations lead to dramatic changes in the way in which nucleosomes pack against each other within the crystal lattice. This has important implications for our understanding of the formation of higher order chromatin structure and its modulation by post-translational modi®cations. Finally, the yeast nucleosome core particle provides a structural context by which to interpret genetic data obtained from yeast. Coordinates have been deposited with the Protein Data Bank under accession number 1ID3.

Recognition Elements in the Histone H3 and H4 Tails for Seven Different Importins

“…New nucleosomes are assembled in the nucleus during S phase as new core histones H2A, H2B, H3, and H4 are synthesized, assembled into H2A/H2B and H3/H4 dimers in the cytoplasm, and then imported into the nucleus for deposition onto replicating chromatin (1)(2)(3)(4)(5)(6)(7)(8). Little is known about cytoplasmic assembly/processing of H2A and H2B, but assembly/processing of H3 and H4 are better understood.…”

Structure et dynamique de la particule cœur de nucléosome

“…Différentes structures cristallographiques de NCP comportant soit des histones d'origines différentes (poulet, levure, humain) soit des variants d'histones, dont les séquences et fonctions sont plus divergentes, ont été établies. Pour les NCP dont on dispose d'une structure, leur structure globale reste similaire [12][13][14][15]. Le mode de fonctionnement global des NCP est donc certainement universel.…”

“…Les sites d'interaction histoneshistones sont éventuellement modifiés. Par exemple, dans la structure des NCP de levure [13], un site d'interaction entre les deux dimères H2A-H2B est absent. De très faibles modifications structurales peuvent néan-moins impliquer des modifications fonctionnelles relativement importantes.…”

Contributions of Sequence to the Higher-Order Structures of DNA

“…The available high-resolution structures provide similarly sketchy hints as to how pairs of nucleosomes may associate along chromatin fibers. Consideration of the close crystallographic contacts on the exposed upper and lower faces of the wedge-shaped histone core (26,48,49) has proven useful in the development of models that account successfully for low-resolution structures and properties of chromatin (17,18).The influence of sequence on the spatial properties of unconstrained, bare, linear DNA chains is more subtle. Consideration of the sequence-dependent structure and deformability of individual basepair steps shifts and narrows the computed distribution of end-to-end distances of a 147-bp stretch of the 601 nucleosome-positioning sequence compared with that of a piece of ideal DNA of the same length (Fig.…”

“…The available high-resolution structures provide similarly sketchy hints as to how pairs of nucleosomes may associate along chromatin fibers. Consideration of the close crystallographic contacts on the exposed upper and lower faces of the wedge-shaped histone core (26,48,49) has proven useful in the development of models that account successfully for low-resolution structures and properties of chromatin (17,18).…”