Which amino acid is commonly modified by acetylation?

Lysine is commonly modified by acetylation, which plays a crucial role in regulating various biological processes, particularly in the context of histone modification and gene expression. Acetylation of lysine residues neutralizes the positive charge of the amino acid, leading to a less tightly packed structure of histones, which in turn promotes a more accessible state of DNA for transcription. This modification can influence cellular processes such as differentiation, proliferation, and apoptosis.

In protein biochemistry, acetylation primarily occurs on the amino group of the lysine side chain, facilitating the formation of an N-acetyl lysine. This modification is significant in various cellular pathways and also contributes to the broader landscape of post-translational modifications that regulate protein function and stability.

Other amino acids listed, such as serine, threonine, and tryptophan, can undergo different types of modifications, but acetylation is most notably associated with lysine due to its specific role in chromatin dynamics and its implications in epigenetic regulation.