Lysines are involved in various biochemical processes, but which of the following is an exception?

Lysine residues in proteins are critical for numerous post-translational modifications that influence various biochemical processes. Each of the modifications listed engages lysine residues in significant ways.

Acetylation, for instance, commonly occurs on lysine residues and can impact gene expression and protein function by neutralizing the positive charge on lysines, leading to changes in how proteins interact with DNA and other molecules.

Methylation also involves lysine residues, where methyl groups are added to the amino group side chain. This modification can regulate protein activity, protein-protein interactions, and is particularly important in the context of histones in chromatin structure and gene regulation.

SUMOylation refers to the covalent attachment of small ubiquitin-like modifiers to lysine residues, modifying protein function, stability, and localization. This process plays roles in various cellular functions, including regulation of the cell cycle and responses to stress.

Phosphorylation, on the other hand, typically occurs on serine, threonine, and tyrosine residues. While phosphorylated residues have profound effects on protein activity and signaling pathways, lysines are not standard targets for phosphorylation. Instead, phosphorylation introduces a negative charge that alters protein interactions and functions, aligning with the properties of the specified