E1, E2, E3 enzymes

E1, E2, and E3 enzymes are part of the cellular process that tags proteins for specific purposes, such as degradation or signaling. E1 enzymes activate a small protein called ubiquitin, preparing it for transfer. E2 enzymes then carry the activated ubiquitin. E3 enzymes are responsible for recognizing the target protein and facilitating the transfer of ubiquitin from E2 to it. This process tags the protein with ubiquitin, signaling it for degradation or altering its activity. Together, these enzymes regulate protein levels and function, maintaining cellular health and response to changing conditions.