CATH Classification

Domain Context

CATH Clusters

Superfamily Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Functional Family Proteasome subunit beta type-6

Enzyme Information

3.4.25.1
Proteasome endopeptidase complex.
based on mapping to UniProt P23724
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 (2)

Q9U8G2
Q9U8G2_9TRYP
Trypanosoma brucei
Proteasome activator protein PA26
P32379
PSA5_YEAST
Saccharomyces cerevisiae S288C
Proteasome subunit alpha type-5

PDB Structure

PDB 1FNT
External Links
Method X-RAY DIFFRACTION
Organism Saccharomyces
Primary Citation
Structural basis for the activation of 20S proteasomes by 11S regulators.
Whitby, F.G., Masters, E.I., Kramer, L., Knowlton, J.R., Yao, Y., Wang, C.C., Hill, C.P.
Nature