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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
The in situ structures of mono-, di-, and trinucleosomes in human heterochromatin
Shujun Cai1, Désirée Böck2, Martin Pilhofer2
1Department of Biological Sciences and Centre for BioImaging Sciences, National University of Singapore, Singapore 117543.
Abstract:
The in situ three-dimensional organization of chromatin at the nucleosome and oligonucleosome levels is unknown. Here we use cryo-electron tomography to determine the in situ structures of HeLa nucleosomes, which have canonical core structures and asymmetric, flexible linker DNA. Subtomogram remapping suggests that sequential nucleosomes in heterochromatin follow irregular paths at the oligonucleosome level. This basic principle of higher-order repressive chromatin folding is compatible with the conformational variability of the two linker DNAs at the single-nucleosome level.
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