histone


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histone

(hĭs`tōn), any of a class of proteinprotein,
any of the group of highly complex organic compounds found in all living cells and comprising the most abundant class of all biological molecules. Protein comprises approximately 50% of cellular dry weight.
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 molecules found in the chromosomes of eukaryotic cellscell,
in biology, the unit of structure and function of which all plants and animals are composed. The cell is the smallest unit in the living organism that is capable of integrating the essential life processes. There are many unicellular organisms, e.g.
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. They complex with the DNA (see nucleic acidnucleic acid,
any of a group of organic substances found in the chromosomes of living cells and viruses that play a central role in the storage and replication of hereditary information and in the expression of this information through protein synthesis.
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) and pack the DNA into tight masses of chromatin, which have the structure of coiled coils, much like a tangled telephone cord. The molecules are strongly basic and of relatively small size. They also serve a function in the transcription of DNA. The histones are rich in the amino acids argininearginine
, organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of proteins.
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 and lysinelysine
, organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer appears in mammalian protein.
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; the five major subtypes of the class differ from one another chiefly in the relative amounts of these two amino acids. They have been greatly conserved during evolution, histone structures vary little in a wide range of organisms.

histone

[′hi‚stōn]
(biochemistry)
Any of the strong, soluble basic proteins of cell nuclei that are precipitated by ammonium hydroxide.
References in periodicals archive ?
Conceptually, we could use the modification, which is the methylation of adenosine residue, as a 'code' in mRNA to target histone modifications to turn gene on or off," Zhao said.
Independent evolution of histone proteins and their prominent sequence variation in ciliates as compared to other animals have made them potential candidate for cross check analysis.
Histone posttranslational modifications (PTMs) are crucial for most DNA-templated processes including transcription, DNA repair, and replication (Kouzarides 2007).
The report provides a snapshot of the global therapeutic landscape for Histone Deacetylase 1 (EC 3.
Removing acetyl groups from lysine amino acids on histones to encourage stronger binding of chromatin structures to suppress gene transcription, and adding acetyl groups to weaken binding of chromatin structures to promote transcriptional activity play an important role in regulation of gene transcription on histones.
The present study of histone acetylation in type 1 diabetes patients focused on classical type 1 diabetes but rarely LADA.
TPA-Elicited Induction of Slug Expression Was Regulated by Histone H3 Acetylation within Its Promoter Region.
Several pharmacological and nonpharmacological epigenetic regulators have also been shown to exert antidepressant effects via inhibition of histone deacetylases.
When the hairless protein was mixed with specific histone substrates under defined reaction conditions, the hairless protein causes a reduction in the level of methylation modification of the histone substrates.
Histone acetylation is catalyzed by histone acetyl transferases (HATs), whereas the opposing reaction is controlled by histone deacetylases (HDACs).
In comparison to DNA methylation, histone modifications are less well characterized in ACC.
G9a histone methyltransferase catalyzes H3K9 methylation in mammals because disruption of the Gga gene resulted in a drastic decrease in H3K9 methylation [24-27].