CATH Classification

Domain Context

CATH Clusters

Superfamily Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Functional Family Proteasome subunit alpha

Enzyme Information

3.4.25.1
Proteasome endopeptidase complex.
based on mapping to UniProt Q53080
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)

Q53079
PSB1_RHOER
Rhodococcus erythropolis
Proteasome subunit beta 1

PDB Structure

PDB 1Q5Q
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Crystal structures of the Rhodococcus proteasome with and without its pro-peptides: implications for the role of the pro-peptide in proteasome assembly.
Kwon, Y.D., Nagy, I., Adams, P.D., Baumeister, W., Jap, B.K.
J.Mol.Biol.