User:Elizabeth Cook/Sandbox 1: Difference between revisions
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== Bromodomains == | == Bromodomains == | ||
The organization and compaction of DNA relies on the fundamental unit of chromatin, the nucleosome. The nucleosome is composed of an octamer of positively charged histone proteins that negatively charged DNA wraps around. Epigenetic modifications are a mechanism for gene regulation in which chemical modifications are added to histone proteins or DNA without altering the underlying DNA sequence. For example, acetylated lysine residues are an epigenetic signal found on the tails of histone proteins that are associated with an up-regulation of gene expression. The negative charge found on the acetyl group neutralizes the positive charge of the lysine residue, disrupting electrostatic interactions, allowing for a more open chromatin state. This allows for increased access to DNA for transcription factors and coactivators. | The organization and compaction of DNA relies on the fundamental unit of chromatin, the nucleosome. The nucleosome is composed of an octamer of positively charged histone proteins that negatively charged DNA wraps around. [[Image:Higherorderchromatin.png|thumb|right|200px|]] | ||
Epigenetic modifications are a mechanism for gene regulation in which chemical modifications are added to histone proteins or DNA without altering the underlying DNA sequence. For example, acetylated lysine residues are an epigenetic signal found on the tails of histone proteins that are associated with an up-regulation of gene expression. The negative charge found on the acetyl group neutralizes the positive charge of the lysine residue, disrupting electrostatic interactions, allowing for a more open chromatin state. This allows for increased access to DNA for transcription factors and coactivators. | |||
[[Image:Postptms.png|center|600px]] | |||
Bromodomains are well characterized and known to recognize acetylated lysine residues. In doing so, the proteins that contain bromodomains are able to respond the information they receive from the epigenetic "signal" via various other domains. These proteins can call upon various regulatory complexes including writers, easers, and transcription factors. | Bromodomains are well characterized and known to recognize acetylated lysine residues. In doing so, the proteins that contain bromodomains are able to respond the information they receive from the epigenetic "signal" via various other domains. These proteins can call upon various regulatory complexes including writers, easers, and transcription factors. | ||
