Proteasome endopeptidase complex

{{technical|date=January 2019}}{{Infobox enzyme

| Name = Proteasome endopeptidase complex

| EC_number = 3.4.25.1

| CAS_number = 140879-24-9

| GO_code =

| image = 1j2q.jpg

| width = 270

| caption = Proteasome core particle, di-heptamer, Archaea

}}

Proteasome endopeptidase complex ({{EC number|3.4.25.1}}, ingensin, macropain, multicatalytic endopeptidase complex, prosome, multicatalytic proteinase (complex), MCP, proteasome, large multicatalytic protease, proteasome organelle, alkaline protease, 26S protease, tricorn proteinase, tricorn protease) is an enzyme.{{cite journal | vauthors = Seemüller E, Lupas A, Stock D, Löwe J, Huber R, Baumeister W | title = Proteasome from Thermoplasma acidophilum: a threonine protease | journal = Science | volume = 268 | issue = 5210 | pages = 579–82 | date = April 1995 | pmid = 7725107 | doi = 10.1126/science.7725107 | bibcode = 1995Sci...268..579S }}{{cite journal | vauthors = Coux O, Tanaka K, Goldberg AL | title = Structure and functions of the 20S and 26S proteasomes | journal = Annual Review of Biochemistry | volume = 65 | pages = 801–47 | date = 1996 | pmid = 8811196 | doi = 10.1146/annurev.bi.65.070196.004101 }}{{cite journal | vauthors = Groll M, Ditzel L, Löwe J, Stock D, Bochtler M, Bartunik HD, Huber R | title = Structure of 20S proteasome from yeast at 2.4 A resolution | journal = Nature | volume = 386 | issue = 6624 | pages = 463–71 | date = April 1997 | pmid = 9087403 | doi = 10.1038/386463a0 | bibcode = 1997Natur.386..463G | s2cid = 4261663 }}{{cite journal | vauthors = Dick TP, Nussbaum AK, Deeg M, Heinemeyer W, Groll M, Schirle M, Keilholz W, Stevanović S, Wolf DH, Huber R, Rammensee HG, Schild H | title = Contribution of proteasomal beta-subunits to the cleavage of peptide substrates analyzed with yeast mutants | journal = The Journal of Biological Chemistry | volume = 273 | issue = 40 | pages = 25637–46 | date = October 1998 | pmid = 9748229 | doi = 10.1074/jbc.273.40.25637 | doi-access = free }} This enzyme catalyses the following chemical reaction

: Cleavage of peptide bonds with very broad specificity

This 20-S protein is composed of 28 subunits arranged in four rings of seven.