FIGURE 46. Nucleosome is the smallest unit of chromatin.


Nucleosome is the smallest unit of chromatin. On the left, the packing of the first few nucleosomes is tight so that the transcription factors do not have access to the DNA wrapped around these nucleosomes. Acetylation of the N-terminal histone protein tails by a histone acetyltransferase reduces its positive charge to form a more relaxed configuration with DNA, which allows the transcription factors and transcriptional machinery access to their recognition sites on the promoters of specific genes to induce transcription.

From: Colonic Motility Dysfunction

Cover of Colonic Motility
Colonic Motility: From Bench Side to Bedside.
Sarna SK.
San Rafael (CA): Morgan & Claypool Life Sciences; 2010.
Copyright © 2010 by Morgan & Claypool Life Sciences.

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