Year: 2019
Type: article
Abstract: The eukaryotic genome is far more than a simple DNA polymer that encodes the sequences of proteins. The genome, or the ensemble of DNA together with all its associated proteins, is an information-processing machine that helps regulate the transcription of the very genes encoded within the DNA.
Chromosomes fold in three dimensions, bringing together segments of DNA separated by great genomic distances; this architecture plays an important role in controlling gene transcription. In different cell types within a single organism, the same chromosomes assume different spatial conformations. In PNAS, Bascom et al. (1) investigate how genes fold in three dimensions using data-driven physical simulations.
The elemental unit of chromosomal organization is the nucleosome: 147 bp of DNA tightly wrapped around eight histone proteins (two copies each of histones H2A, H2B, H3, and H4). Histone proteins undergo a vast repertoire of covalent posttranslational modifications on many of their residues, particularly along the flexible N-terminal domain typically referred to as the histone tail. These epigenetic modifications affect the structural dynamics of histones (2) and are known to be involved in gene regulation and to correlate with genome architecture (3). A DNA linker connects nucleosomes to one another; the length of the linker region is variable and also known to affect the structural organization of the genome. A third factor that affects the structural dynamics of the chromatin fiber is the binding of another protein of the histone family, the linker histone, to the DNA.
Bascom et al. (1) integrate the experimental …
[↵][1]1Email: michele.dipierro{at}rice.edu.
[1]: #xref-corresp-1-1
Author: Michele Di Pierro
Institutions: Center for Theoretical Biological Physics, Rice University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2916342507