Pup grows up: in vitro characterization of the degradation of pupylated proteins.

The article presents information on studies related to prokaryotic ubiquitin-like protein (Pup)-proteasome degradation system in vitro. It is stated that the degradation signal has two parts including a recognition element that will bind to the ATP-dependent protease and the site where degradation actually initiates. It is stated that a paper by E. Weber-Ban and colleagues shows that the Pup chain is recognized by the Mpa ATPase.