Function
Proteasome (PRTS) are large protein complexes which degrade unneeded proteins into small polypeptides[1]. The 26S PRTS is composed of a central 20S core particle which contains 4 stacked rings each with several members and two 19S caps. The 19S cap is composed of a base with 10 proteins six of which are ATPases and a lid which contains 9 proteins which bind polyubiquitin.
- 13S PRTS is a PRTS core intermediate containing α ring, partial β ring and 3 chaperones[2].
- 15S PRTS is half of an 20S PRTS and upon dimerisation forms the mature 20S PRTS[3].
- 19S PRTS is the regulatory paricle pf PRTSwhich recognizes the ubiquinated substrates destined for proteolysis[4].
- Immunoproteasome is PRTS variant induced by inflamation[5].
For more details see 3unb.
Structural highlights
The core particle two outer rings contain 7 α subunits (Y7, Y13, PRE6, PRE5, PUP2, C1, C7-α) which form the PRTS gate. The two inner rings contain 7 β subunits (PRE2, PRE4, PRE3, PUP1, PUP3, C5, C11) with protease activity[6].
3D Structures of Proteasome
Proteasome 3D structures
See Also
PROTAC (Proteolysis-Targeting Chimera), an alternative to conventional enzyme inhibitors, by enabling proteasome induced degradation of the target protein.
- ↑ Saeki Y, Tanaka K. Assembly and function of the proteasome. Methods Mol Biol. 2012;832:315-37. doi: 10.1007/978-1-61779-474-2_22. PMID:22350895 doi:https://dx.doi.org/10.1007/978-1-61779-474-2_22
- ↑ Schnell HM, Walsh RM Jr, Rawson S, Kaur M, Bhanu MK, Tian G, Prado MA, Guerra-Moreno A, Paulo JA, Gygi SP, Roelofs J, Finley D, Hanna J. Structures of chaperone-associated assembly intermediates reveal coordinated mechanisms of proteasome biogenesis. Nat Struct Mol Biol. 2021 May;28(5):418-425. PMID:33846632 doi:10.1038/s41594-021-00583-9
- ↑ Tundo GR, Sbardella D, Santoro AM, Coletta A, Oddone F, Grasso G, Milardi D, Lacal PM, Marini S, Purrello R, Graziani G, Coletta M. The proteasome as a druggable target with multiple therapeutic potentialities: Cutting and non-cutting edges. Pharmacol Ther. 2020 Sep;213:107579. PMID:32442437 doi:10.1016/j.pharmthera.2020.107579
- ↑ Ehlinger A, Walters KJ. Structural insights into proteasome activation by the 19S regulatory particle. Biochemistry. 2013 May 28;52(21):3618-28. PMID:23672618 doi:10.1021/bi400417a
- ↑ Ferrington DA, Gregerson DS. Immunoproteasomes: structure, function, and antigen presentation. Prog Mol Biol Transl Sci. 2012;109:75-112. doi: , 10.1016/B978-0-12-397863-9.00003-1. PMID:22727420 doi:https://dx.doi.org/10.1016/B978-0-12-397863-9.00003-1
- ↑ Coux O, Tanaka K, Goldberg AL. Structure and functions of the 20S and 26S proteasomes. Annu Rev Biochem. 1996;65:801-47. PMID:8811196 doi:https://dx.doi.org/10.1146/annurev.bi.65.070196.004101