ID   PSB_METS3               Reviewed;         204 AA.
AC   A5UM14;
DT   10-AUG-2010, integrated into UniProtKB/Swiss-Prot.
DT   10-JUL-2007, sequence version 1.
DT   25-MAY-2022, entry version 78.
DE   RecName: Full=Proteasome subunit beta {ECO:0000255|HAMAP-Rule:MF_02113};
DE            EC=3.4.25.1 {ECO:0000255|HAMAP-Rule:MF_02113};
DE   AltName: Full=20S proteasome beta subunit {ECO:0000255|HAMAP-Rule:MF_02113};
DE   AltName: Full=Proteasome core protein PsmB {ECO:0000255|HAMAP-Rule:MF_02113};
DE   Flags: Precursor;
GN   Name=psmB {ECO:0000255|HAMAP-Rule:MF_02113}; OrderedLocusNames=Msm_1037;
OS   Methanobrevibacter smithii (strain ATCC 35061 / DSM 861 / OCM 144 / PS).
OC   Archaea; Euryarchaeota; Methanomada group; Methanobacteria;
OC   Methanobacteriales; Methanobacteriaceae; Methanobrevibacter.
OX   NCBI_TaxID=420247;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 35061 / DSM 861 / OCM 144 / PS;
RX   PubMed=17563350; DOI=10.1073/pnas.0704189104;
RA   Samuel B.S., Hansen E.E., Manchester J.K., Coutinho P.M., Henrissat B.,
RA   Fulton R., Latreille P., Kim K., Wilson R.K., Gordon J.I.;
RT   "Genomic and metabolic adaptations of Methanobrevibacter smithii to the
RT   human gut.";
RL   Proc. Natl. Acad. Sci. U.S.A. 104:10643-10648(2007).
CC   -!- FUNCTION: Component of the proteasome core, a large protease complex
CC       with broad specificity involved in protein degradation.
CC       {ECO:0000255|HAMAP-Rule:MF_02113}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Cleavage of peptide bonds with very broad specificity.;
CC         EC=3.4.25.1; Evidence={ECO:0000255|HAMAP-Rule:MF_02113};
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. {ECO:0000255|HAMAP-Rule:MF_02113}.
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.
CC       {ECO:0000255|HAMAP-Rule:MF_02113}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_02113}.
CC   -!- SIMILARITY: Belongs to the peptidase T1B family. {ECO:0000255|HAMAP-
CC       Rule:MF_02113}.
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DR   EMBL; CP000678; ABQ87242.1; -; Genomic_DNA.
DR   RefSeq; WP_011954251.1; NC_009515.1.
DR   AlphaFoldDB; A5UM14; -.
DR   SMR; A5UM14; -.
DR   STRING; 420247.Msm_1037; -.
DR   MEROPS; T01.002; -.
DR   EnsemblBacteria; ABQ87242; ABQ87242; Msm_1037.
DR   GeneID; 5215867; -.
DR   KEGG; msi:Msm_1037; -.
DR   PATRIC; fig|420247.28.peg.1035; -.
DR   eggNOG; arCOG00970; Archaea.
DR   HOGENOM; CLU_035750_7_2_2; -.
DR   OMA; VDKTGPH; -.
DR   Proteomes; UP000001992; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0019774; C:proteasome core complex, beta-subunit complex; IEA:UniProtKB-UniRule.
DR   GO; GO:0004298; F:threonine-type endopeptidase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0010498; P:proteasomal protein catabolic process; IEA:UniProtKB-UniRule.
DR   Gene3D; 3.60.20.10; -; 1.
DR   HAMAP; MF_02113_A; Proteasome_B_A; 1.
DR   InterPro; IPR029055; Ntn_hydrolases_N.
DR   InterPro; IPR019983; Pept_T1A_Psome_bsu_arc.
DR   InterPro; IPR000243; Pept_T1A_subB.
DR   InterPro; IPR016050; Proteasome_bsu_CS.
DR   InterPro; IPR001353; Proteasome_sua/b.
DR   InterPro; IPR023333; Proteasome_suB-type.
DR   Pfam; PF00227; Proteasome; 1.
DR   PRINTS; PR00141; PROTEASOME.
DR   SUPFAM; SSF56235; SSF56235; 1.
DR   TIGRFAMs; TIGR03634; arc_protsome_B; 1.
DR   PROSITE; PS00854; PROTEASOME_BETA_1; 1.
DR   PROSITE; PS51476; PROTEASOME_BETA_2; 1.
PE   3: Inferred from homology;
KW   Autocatalytic cleavage; Cytoplasm; Hydrolase; Protease; Proteasome;
KW   Threonine protease; Zymogen.
FT   PROPEP          1..8
FT                   /note="Removed in mature form; by autocatalysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02113"
FT                   /id="PRO_0000397332"
FT   CHAIN           9..204
FT                   /note="Proteasome subunit beta"
FT                   /id="PRO_0000397333"
FT   ACT_SITE        9
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02113"
SQ   SEQUENCE   204 AA;  21928 MW;  C59BFB88CA0EF691 CRC64;
     MDDKILEGTT TVGITCKDGV VFASERRASM GNLVAHKVAE KIFKINDHIV TTIAGSVGDA
     QNLMKIIEAE VSLYQMRNND KISVKAAASV TANILRSGPM YVQTLLGGMD GDKPSLYSLD
     PAGGMIEDTY ISTGSGSIVA YGVLEDRYHE EITTDEGLEI AVRAIKAASE RDTFSGNGYL
     VAKVTKDGFE MLDKEKVNDI VAKI