obsolete proteasome regulatory particle (sensu Bacteria) true proteasome regulatory particle (sensu Bacteria) GO:0000504 OBSOLETE. A multisubunit complex that recognizes and unfolds ubiquitinated proteins, and translocates them to the core complex in an ATP dependent manner. As in, but not restricted to, the taxon Bacteria (Bacteria, ncbi_taxonomy_id:2). cellular_component 26S proteasome This term was made obsolete because there is no ubiquitin in bacteria and they do not have proteasome regulatory particles. Instead they have proteasome-activating nucleotidase.