Chromatin's structure plays an important regulatory role in DNA template-dependent processes including transcription, replication, recombination, repair, segregation, chromosomal stability, cell cycle progression, and epigenetic silencing.1-3 Many factors can induce remodeling (changes in chromatin structure) including histone modification and the binding of numerous non-histone proteins that are loosely termed the transcriptional apparatus.
Histones contain two distinct domains. The proteins' amino-terminal tails, which protrude from the nucleosome core, are unstructured and highly positively charged owing to the presence of several lysine and arginine residues. Conversely, the histone core domain is globular and responsible for the histone:histone interactions involved in nucleosome formation.2 A variety of well-conserved post-translational modifications occur in the histone tail domain, including acetylation, phosphorylation, methylation, ribosylation, ubiquitinylation, and glycosylation; the most well-studied of these is the acetylation of histone tail domains on specific lysine residues.1-5 The conventional wisdom holds that these modifications alter the strength of the interaction between DNA ...
