CATH Domain 4qltI00

CATH Classification

Level	CATH Code	Description
	3	Alpha Beta
	3.60	4-Layer Sandwich
	3.60.20	Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
	3.60.20.10	Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1

Domain Context

CATH Clusters

Superfamily	Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Functional Family	Proteasome subunit beta type-3

Enzyme Information

3.4.25.1

Proteasome endopeptidase complex.

based on mapping to UniProt P25451

Cleavage of peptide bonds with very broad specificity.

-!- A 20-S protein composed of 28 subunits arranged in four rings of seven. -!- The outer rings are composed of alpha subunits, but the beta subunits forming the inner rings are responsible for peptidase activity. -!- In eukaryotic organisms there are up to seven different types of beta subunits, three of which may carry the N-terminal threonine residues that are the nucleophiles in catalysis, and show different specificities. -!- The molecule is barrel-shaped, and the active sites are on the inner surfaces. -!- Terminal apertures restrict access of substrates to the active sites. -!- Inhibited by mercurial reagents and some inhibitors of serine endopeptidases. -!- Belongs to peptidase family T1. -!- Formerly EC 3.4.22.21, EC 3.4.24.5 and EC 3.4.99.46.

UniProtKB Entries (1)

P21243

PSA1_YEAST

Saccharomyces cerevisiae S288C

Proteasome subunit alpha type-1

PDB Structure

PDB	4QLT
External Links	PDBSum Proteopedia
Method	X-RAY DIFFRACTION
Organism
Primary Citation	Structure-based design of beta 1i or beta 5i specific inhibitors of human immunoproteasomes De Bruin, G., Huber, E.M., Xin, B.T., Van Rooden, E.J., Al-Ayed, K., Kim, K.B., Kisselev, A.F., Driessen, C., Van der Stelt, M., Van der Marel, G.A., Groll, M., Overkleeft, H.S. J.Med.Chem.