proteasome

The outer membrane of the proteasome admits only proteins carrying a ubiquitin molecule, which detaches before entering the proteasome and is reused.

…accompanies the protein to a proteasome, which is essentially a structure of powerful enzymes that break the protein into its component amino acids. The outer membrane of the proteasome admits only proteins carrying a ubiquitin molecule, which detaches before entering the proteasome and is reused.

…and accompanies it to a proteasome—essentially a sac of powerful enzymes that divide the protein into its component amino acids. The outer membrane of the proteasome admits only proteins carrying a ubiquitin molecule. The ubiquitin molecule detaches before entering the proteasome, and cells reuse it to tag another protein for…