Acetyltransferases are a group of enzymes that facilitate the transfer of an acetyl group from one molecule to another. This process is essential in various biological reactions, including the modification of proteins and the metabolism of drugs. By adding an acetyl group, these enzymes can alter the function and activity of target molecules, influencing cellular processes. These enzymes play a crucial role in gene regulation and cell signaling. For example, histone acetyltransferases modify histones, which can affect gene expression by altering the structure of chromatin. Overall, acetyltransferases are vital for maintaining cellular homeostasis and regulating numerous biochemical pathways.