ID   PSB_METRM               Reviewed;         207 AA.
AC   D3E0A3;
DT   10-AUG-2010, integrated into UniProtKB/Swiss-Prot.
DT   23-MAR-2010, sequence version 1.
DT   25-MAY-2022, entry version 57.
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=mru_1977;
OS   Methanobrevibacter ruminantium (strain ATCC 35063 / DSM 1093 / JCM 13430 /
OS   OCM 146 / M1) (Methanobacterium ruminantium).
OC   Archaea; Euryarchaeota; Methanomada group; Methanobacteria;
OC   Methanobacteriales; Methanobacteriaceae; Methanobrevibacter.
OX   NCBI_TaxID=634498;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 35063 / DSM 1093 / JCM 13430 / OCM 146 / M1;
RX   PubMed=20126622; DOI=10.1371/journal.pone.0008926;
RA   Leahy S.C., Kelly W.J., Altermann E., Ronimus R.S., Yeoman C.J.,
RA   Pacheco D.M., Li D., Kong Z., McTavish S., Sang C., Lambie S.C.,
RA   Janssen P.H., Dey D., Attwood G.T.;
RT   "The genome sequence of the rumen methanogen Methanobrevibacter ruminantium
RT   reveals new possibilities for controlling ruminant methane emissions.";
RL   PLoS ONE 5:E8926-E8926(2010).
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; CP001719; ADC47827.1; -; Genomic_DNA.
DR   RefSeq; WP_012956775.1; NC_013790.1.
DR   AlphaFoldDB; D3E0A3; -.
DR   SMR; D3E0A3; -.
DR   STRING; 634498.mru_1977; -.
DR   MEROPS; T01.002; -.
DR   PRIDE; D3E0A3; -.
DR   EnsemblBacteria; ADC47827; ADC47827; mru_1977.
DR   GeneID; 8771647; -.
DR   KEGG; mru:mru_1977; -.
DR   PATRIC; fig|634498.28.peg.1978; -.
DR   eggNOG; arCOG00970; Archaea.
DR   HOGENOM; CLU_035750_7_2_2; -.
DR   OMA; VDKTGPH; -.
DR   OrthoDB; 89767at2157; -.
DR   Proteomes; UP000008680; 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   Reference proteome; Threonine protease; Zymogen.
FT   PROPEP          1..9
FT                   /note="Removed in mature form; by autocatalysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02113"
FT                   /id="PRO_0000397330"
FT   CHAIN           10..207
FT                   /note="Proteasome subunit beta"
FT                   /id="PRO_0000397331"
FT   ACT_SITE        10
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02113"
SQ   SEQUENCE   207 AA;  21975 MW;  2B3E8F1CAB9883EF CRC64;
     MSNKNTFEGT TTVGITCKDG VVFASERRAS MGNLVAHKVA EKIFKIDNHI AATIAGSVAD
     AQTLMKVISA ETSLYRLRNG KDISLEAAAA VSSNILHSSP AYVQTLIGGV DDTGASIYSL
     DAAGGMIKDT FISTGSGSTF AYGVLEDRFY EDITVEEATE VAIRAIKAAT ERDTFSGNGF
     LVANVTKDGF KMLEKEEVDA IIEKINS