CATH Classification

Domain Context

CATH Clusters

Superfamily Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Functional Family Proteasome subunit alpha type-4

Enzyme Information

3.4.25.1
Proteasome endopeptidase complex.
based on mapping to UniProt P40303
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)

P25451
PSB3_YEAST
Saccharomyces cerevisiae S288C
Proteasome subunit beta type-3

PDB Structure

PDB 4G4S
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Structure of a Proteasome Pba1-Pba2 Complex: IMPLICATIONS FOR PROTEASOME ASSEMBLY, ACTIVATION, AND BIOLOGICAL FUNCTION.
Stadtmueller, B.M., Kish-Trier, E., Ferrell, K., Petersen, C.N., Robinson, H., Myszka, D.G., Eckert, D.M., Formosa, T., Hill, C.P.
J.Biol.Chem.
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