Bromodomain

Bromodomain

A bromodomain is a protein domain that recognizes and binds to acetylated lysine residues, such as those found in histone tails. This interaction plays a crucial role in the regulation of gene expression by influencing chromatin structure and function.

Structure

Bromodomains are typically composed of approximately 110 amino acids and form a conserved left-handed bundle of four alpha helices. The acetyl-lysine binding pocket is located at the surface of the domain and is characterized by a hydrophobic cavity that accommodates the acetyl group.

Function

Bromodomains are found in a variety of proteins, including histone acetyltransferases, chromatin remodelers, and transcriptional coactivators. By binding to acetylated lysines on histone tails, bromodomains facilitate the recruitment of these proteins to specific regions of chromatin, thereby influencing gene expression.

Biological Significance

The interaction between bromodomains and acetylated lysines is a key mechanism in the regulation of chromatin dynamics and epigenetic modifications. This interaction is essential for processes such as DNA repair, transcriptional activation, and cell cycle progression.

Clinical Relevance

Bromodomains have been implicated in various diseases, including cancer, inflammatory diseases, and neurological disorders. Inhibitors targeting bromodomains, such as BET inhibitors, are being developed as potential therapeutic agents for these conditions.

Examples of Bromodomain-Containing Proteins

• BRD2
• BRD3
• BRD4
• PCAF
• TAF1

Research and Development

Ongoing research aims to better understand the specific roles of bromodomains in different cellular contexts and to develop more selective and potent inhibitors for therapeutic use.

See Also

• Chromatin
• Epigenetics
• Histone modification
• Transcription regulation