AC   MF_02113;
DC   Protein; auto
c?   <OC:Bacteria>
TR   HAMAP; MF_02113_B; -; 1; level=0
c?   <OC:Archaea>
TR   HAMAP; MF_02113_A; -; 1; level=0
XX
Names: Proteasome_B
XX
ID   PSB
case <OC:Bacteria>
DE   RecName: Full=Proteasome subunit beta;
DE            EC=3.4.25.1;
DE   AltName: Full=20S proteasome beta subunit;
DE   AltName: Full=Proteasome core protein PrcB;
DE   Flags: Precursor;
GN   Name=prcB;
end case
case <OC:Archaea>
DE   RecName: Full=Proteasome subunit beta;
DE            EC=3.4.25.1;
DE   AltName: Full=20S proteasome beta subunit;
DE   AltName: Full=Proteasome core protein PsmB;
DE   Flags: Precursor;
GN   Name=psmB;
end case
XX
CC   -!- FUNCTION: Component of the proteasome core, a large protease complex
CC       with broad specificity involved in protein degradation.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Cleavage of peptide bonds with very broad specificity.;
CC         EC=3.4.25.1;
case <OC:Bacteria>
CC   -!- ACTIVITY REGULATION: The formation of the proteasomal ATPase ARC-20S
CC       proteasome complex, likely via the docking of the C-termini of ARC into
CC       the intersubunit pockets in the alpha-rings, may trigger opening of the
CC       gate for substrate entry. Interconversion between the open-gate and
CC       close-gate conformations leads to a dynamic regulation of the 20S
CC       proteasome proteolysis activity.
CC   -!- PATHWAY: Protein degradation; proteasomal Pup-dependent pathway.
CC   -!- SUBUNIT: The 20S proteasome core is composed of 14 alpha and 14 beta
CC       subunits that assemble into four stacked heptameric rings, resulting in
CC       a barrel-shaped structure. The two inner rings, each composed of seven
CC       catalytic beta subunits, are sandwiched by two outer rings, each
CC       composed of seven alpha subunits. The catalytic chamber with the active
CC       sites is on the inside of the barrel. Has a gated structure, the ends
CC       of the cylinder being occluded by the N-termini of the alpha-subunits.
CC       Is capped by the proteasome-associated ATPase, ARC.
end case
case <OC:Archaea>
CC   -!- ACTIVITY REGULATION: The formation of the proteasomal ATPase PAN-20S
CC       proteasome complex, via the docking of the C-termini of PAN into the
CC       intersubunit pockets in the alpha-rings, triggers opening of the gate
CC       for substrate entry. Interconversion between the open-gate and close-
CC       gate conformations leads to a dynamic regulation of the 20S proteasome
CC       proteolysis activity.
CC   -!- SUBUNIT: The 20S proteasome core is composed of 14 alpha and 14 beta
CC       subunits that assemble into four stacked heptameric rings, resulting in
CC       a barrel-shaped structure. The two inner rings, each composed of seven
CC       catalytic beta subunits, are sandwiched by two outer rings, each
CC       composed of seven alpha subunits. The catalytic chamber with the active
CC       sites is on the inside of the barrel. Has a gated structure, the ends
CC       of the cylinder being occluded by the N-termini of the alpha-subunits.
CC       Is capped at one or both ends by the proteasome regulatory ATPase, PAN.
end case
CC   -!- SUBCELLULAR LOCATION: Cytoplasm.
CC   -!- SIMILARITY: Belongs to the peptidase T1B family.
XX
DR   PROSITE; PS00854; PROTEASOME_BETA_1; 1; trigger=no
DR   PROSITE; PS51476; PROTEASOME_BETA_2; 1; trigger=no
DR   Pfam; PF00227; Proteasome; 1; trigger=no
DR   PRINTS; PR00141; PROTEASOME; 1; trigger=no
DR   NCBIfam; TIGR03634; Arc_protsome_B; 1; trigger=no
DR   NCBIfam; TIGR03690; 20S_bact_beta; 1; trigger=no
XX
KW   Autocatalytic cleavage
KW   Cytoplasm
KW   Hydrolase
KW   Protease
KW   Proteasome
KW   Threonine protease
KW   Zymogen
XX
GO   GO:0004298; F:threonine-type endopeptidase activity
GO   GO:0010498; P:proteasomal protein catabolic process
case <OC:Bacteria>
GO   GO:0019941; P:modification-dependent protein catabolic process
end case
GO   GO:0005737; C:cytoplasm
GO   GO:0019774; C:proteasome core complex, beta-subunit complex
XX
FT   From: PSB_THEAC (P28061)
case <OC:Archaea>
FT   PROPEP          Nter..8
FT                   /note="Removed in mature form; by autocatalysis"
FT   CHAIN           9..Cter
FT                   /note="Proteasome subunit beta"
FT   ACT_SITE        9
FT                   /note="Nucleophile"
FT   Condition: T
end case
FT   From: PSB_MYCTU (P9WHT9)
case <OC:Bacteria>
FT   PROPEP          Nter..57
FT                   /note="Removed in mature form; by autocatalysis"
FT   CHAIN           58..Cter
FT                   /note="Proteasome subunit beta"
FT   ACT_SITE        58
FT                   /note="Nucleophile"
FT   Condition: T
end case
XX
case <OC:Bacteria>
Size: 269-306;
end case
case <OC:Archaea>
Size: 193-243;
end case
Related: None;
Template: P28061; P9WHT9; Q9P996; Q58634; D4GYZ1; Q53079; Q53083;
Scope:
 Archaea
 Bacteria; Actinomycetota
Fusion:
 Nter: None
 Cter: None
Duplicate: in AERPE, CALMQ, CENSY, DESA1, HALMA, HALTV, HYPBU, IGNH4, KORCO,
 METS5, NITMS, PYRAB, PYRAE, PYRAR, PYRCJ, PYRFU, PYRHO, PYRIL, THEKO, RHOER,
 SALTO, STAMF, STRAW, SULAC, SULIA, SULID, SULIK, SULIL, SULIM, SULIN, SULIY,
 SACS9, SACS2, SULTO, THECD, THEGJ, PYRNV, THEON, THEPD, THESM
Plasmid: None
Comments: Subunit alpha of the proteasome core is in MF_00289.
XX
# Revision 1.18 2023/06/01
//