China
Africa
Explore chapters and articles related to this topic
Naturally Occurring Histone Deacetylase (HDAC) Inhibitors in the Treatment of Cancers
Published in Namrita Lall, Medicinal Plants for Cosmetics, Health and Diseases, 2022
Sujatha Puttalingaiah, Murthy V. Greeshma, Mahadevaswamy G. Kuruburu, Venugopal R. Bovilla, SubbaRao V. Madhunapantula
Each nucleosome bead is separated from the next bead by a 54-base pair linker DNA. The linker DNA contains a single H1 histone protein, which seals off the two complete DNA turns (200 base pairs long) (Hergeth and Schneider, 2015). The addition of one H1 wraps another 20 base pairs, resulting in two full turns around the octamer, and forms a structure called ‘chromatosome.’ Long eukaryotic DNA wrapped around the histone proteins leads to the formation of a compact chromosome (Maeshima and Eltsov, 2008).
Genetics in neonatal surgical practice
Published in Prem Puri, Newborn Surgery, 2017
To successfully package vast amounts of DNA into each cell nucleus, it must be compressed and compacted. The first coiling of DNA is in the form of the double helix. The negatively charged DNA double helix is then bound tightly to and wound 1.65 times around a core of eight positively charged histone proteins to form a nucleosome. The addition of another histone completes the second winding of DNA about the histone core to form a chromatosome. These units stack up and form loops of approximately 300 nm. These are stacked, compressed, and folded into fibers of 250 nm wide. These fibers are then tightly coiled to form a chromatid. Two sister chromatids make up a single chromosome, joined by a centromere. The centromere represents a division along the chromatids in a chromosome, creating a short arm “p” and a long arm “q.”
In vitro cytotoxicity of polyphenols from Datura innoxia aqueous leaf-extract on human leukemia K562 cells: DNA and nuclear proteins as targets
Published in Drug and Chemical Toxicology, 2020
Elham Chamani, Roshanak Ebrahimi, Khatereh Khorsandi, Azadeh Meshkini, Asghar Zarban, Gholamreza Sharifzadeh
Studies have shown that DNA is a pharmacological target of many of the drugs currently in clinical use or in advanced clinical trials (Hurley and Boyd 1988, Sirajuddin et al. 2013). In the eukaryotes, nuclear DNA interacts with histone proteins and forms a nucleoprotein complex known as chromatin. Chromatin arranges the nuclear genome into a restricted volume. The first level of chromatin organization consists of DNA-folding around histone proteins to shape the fundamental unit of the chromatin, the nucleosome (Hübner et al. 2013). In a nucleosome, 147 bp of DNA are enfolded in an octamer with two copies of four core histone proteins (H2A, H2B, H3, and H4) (Nair and Kumar 2012). As a linker histone, histone H1 surrounds the chromatosome by protecting the internucleosomal linker DNA near the nucleosome entry-exit point (Dixon et al. 2016, Kalashnikova et al. 2016).
Gordon H. Dixon’s trace in my personal career and the quantic jump experienced in regulatory information
Published in Systems Biology in Reproductive Medicine, 2018
H1 histones are densely distributed along the entire length of chromosomal DNA and bind preferentially to CpG Methylation sites (Jost and Hofsteenge 1992). H1 binds to the nucleosome to form the next structural unit of metazoan chromatin, the chromatosome, which help chromatin to fold into higher-order structures (Fyodorov et al. 2018). It was not till 2015 that the first near-atomic resolution crystal structure of a chromatosome core particle and an 11 Å resolution cryo-electron microscopy-derived structure of the 30 nm nucleosome array was published (Zhou et al. 2015). It revealed unprecedented details about linker histone interactions with the nucleosome and the organization of higher-order chromatin structures. In addition, linker histones with important implications in epigenetic regulation, regulation of DNA replication, DNA repair, and genome stability were uncovered (Kasinsky et al. 2001; Sancho et al. 2008; Hergeth and Schneider 2015; Izzo and Schneider 2016; Fyodorov et al. 2018).