Y, or Proteasome subunit beta 6, is a human gene encoded by PSMB6. It may also be known as: Proteasome subunit beta type-6; Multicatalytic endopeptidase complex delta chain; Proteasome delta chain; Proteasome subunit Y; Macropain delta chain; Proteasome subunit beta type-6 ; DELTA; LMPY; proteasome (prosome, macropain) subunit, beta type, 6. The encoded protein is an enzyme with an amino acid length of 239 and a mass of 25.4 kDa. Other isoforms may exist. Y is a member of the Peptidase T1B family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog.