Histones are a class of evolutionarily conserved nuclear proteins. Histone octamer wrapped by DNA sequence forms the nucleosome, the basic building blocks of eukaryotic chromatin. The nucleosomes keep the DNA in a condensed state, maintain the integrity of the genome, and ensure proper DNA replication, transcription, recombination and repair. Nucleosomes can regulate the biological processes of the cell through a number of distinct post-translational modifications(PTMs) and turnovers of histone variants. Al...