HAMAP

Accession	MF_02113
Dates	2-JUL-2010 (Created) 8-JUL-2011 (Last updated, Version 4)

Data class

Protein

Predictors

HAMAP; MF_02113_B; [distribution of match scores in UniProtKB];[seed alignment for MF_02113_B]

Predictors

HAMAP; MF_02113_A; [distribution of match scores in UniProtKB];[seed alignment for MF_02113_A]

Names

Proteasome_B

Identifier

PSB

Protein name

RecName: Full=Proteasome subunit beta; EC=3.4.25.1; AltName: Full=20S proteasome beta subunit; AltName: Full=Proteasome core protein PrcB; Flags: Precursor;

Gene name

prcB

Protein name

RecName: Full=Proteasome subunit beta; EC=3.4.25.1; AltName: Full=20S proteasome beta subunit; AltName: Full=Proteasome core protein PsmB; Flags: Precursor;

Gene name

psmB

FUNCTION: Component of the proteasome core, a large protease complex with broad specificity involved in protein degradation (By similarity).

CATALYTIC ACTIVITY: Cleavage of peptide bonds with very broad specificity.

ENZYME REGULATION: The formation of the proteasomal ATPase ARC-20S proteasome complex, likely via the docking of the C-termini of ARC into the intersubunit pockets in the alpha-rings, may trigger opening of the gate for substrate entry. Interconversion between the open-gate and close-gate conformations leads to a dynamic regulation of the 20S proteasome proteolysis activity (By similarity).

PATHWAY: Protein degradation; proteasomal pup-dependent pathway.

SUBUNIT: The 20S proteasome core is composed of 14 alpha and 14 beta subunits that assemble into four stacked heptameric rings, resulting in a barrel-shaped structure. The two inner rings, each composed of seven catalytic beta subunits, are sandwiched by two outer rings, each composed of seven alpha subunits. The catalytic chamber with the active sites is on the inside of the barrel. Has a gated structure, the ends of the cylinder being occluded by the N-termini of the alpha-subunits. Is capped by the proteasome-associated ATPase, ARC (By similarity).

ENZYME REGULATION: The formation of the proteasomal ATPase PAN-20S proteasome complex, via the docking of the C-termini of PAN into the intersubunit pockets in the alpha-rings, triggers opening of the gate for substrate entry. Interconversion between the open-gate and close-gate conformations leads to a dynamic regulation of the 20S proteasome proteolysis activity (By similarity).

SUBUNIT: The 20S proteasome core is composed of 14 alpha and 14 beta subunits that assemble into four stacked heptameric rings, resulting in a barrel-shaped structure. The two inner rings, each composed of seven catalytic beta subunits, are sandwiched by two outer rings, each composed of seven alpha subunits. The catalytic chamber with the active sites is on the inside of the barrel. Has a gated structure, the ends of the cylinder being occluded by the N-termini of the alpha-subunits. Is capped at one or both ends by the proteasome regulatory ATPase, PAN (By similarity).

SUBCELLULAR LOCATION: Cytoplasm (By similarity).

SIMILARITY: Belongs to the peptidase T1B family.

PROSITE	PS00854; PROTEASOME_B_1; 1; PS51476; PROTEASOME_B_2; 1;
Pfam	PF00227; Proteasome; 1;
PRINTS	PR00141; PROTEASOME; 1;
TIGRFAMs	TIGR03634; Arc_protsome_B; 1; TIGR03690; 20S_bact_beta; 1;

Autocatalytic cleavage, Cytoplasm, Hydrolase, Protease, Proteasome, Threonine protease, Zymogen.

GO:0004298; Molecular function: threonine-type endopeptidase activity.
GO:0010498; Biological process: proteasomal protein catabolic process.

GO:0019941; Biological process: modification-dependent protein catabolic process.

GO:0005737; Cellular component: cytoplasm.
GO:0019774; Cellular component: proteasome core complex, beta-subunit complex.

From: PSB_THEAC (P28061)
Key		From		To		Description		Condition		FTGroup
PROPEP		Nter		8		Removed in mature form; by autocatalysis (By similarity)
CHAIN		9		Cter		Proteasome subunit beta
ACT_SITE		9		9		Nucleophile (By similarity)		T

From: PSB_MYCTU (O33245)
Key		From		To		Description		Condition		FTGroup
PROPEP		Nter		57		Removed in mature form; by autocatalysis (By similarity)
CHAIN		58		Cter		Proteasome subunit beta
ACT_SITE		58		58		Nucleophile (By similarity)		T

Size range:

269-306 amino acids

Size range:

193-243 amino acids

Related UniRules:	None
Template:	P28061 (PSB_THEAC); O33245 (PSB_MYCTU); Q9P996 (PSB_ARCFU); Q58634 (PSB_METJA); D4GYZ1 (PSB_HALVD); Q53079 (PSB1_RHOER); Q53083 (PSB2_RHOER): [Recover all]
Scope:	Archaea Bacteria; Actinobacteria
Fusion:	Nter: None; Cter: None
Duplicate:	in AERPE, CALMQ, CENSY, DESK1, HALMA, HALTV, HYPBU, IGNH4, KORCO, METS5, NITMS, PYRAB, PYRAE, PYRAR, PYRCJ, PYRFU, PYRHO, PYRIL, PYRKO, RHOER, SALTO, STAMF, STRAW, SULAC, SULIA, SULID, SULIK, SULIL, SULIM, SULIN, SULIY, SULS9, SULSO, SULTO, THECD, THEGJ, THENV, THEON, THEPD, THESM
Plasmid encoded:	None
Comments:	Subunit alpha of the proteasome core is in MF_00289.