…first step a molecule called ubiquitin (from the Latin ubique, meaning “everywhere,” because it occurs in so many different cells and organisms) attaches to a protein targeted for destruction and accompanies it to a proteasome—essentially a sac of powerful enzymes that break the protein into its component amino acids. The…

…begins when a molecule called ubiquitin (from the Latin ubique, meaning “everywhere,” because it occurs in so many different cells and organisms) attaches itself to the protein targeted for destruction. It then accompanies the protein to a proteasome, which is essentially a structure of powerful enzymes that break the protein…

…first step a molecule called ubiquitin (from the Latin ubique, meaning “everywhere,” because it occurs in so many different cells and organisms) attaches to the protein targeted for destruction and accompanies it to a proteasome—essentially a sac of powerful enzymes that divide the protein into its component amino acids. The…