ID   PSB_NANEQ               Reviewed;         196 AA.
AC   Q74MP5;
DT   10-AUG-2010, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   25-MAY-2022, entry version 95.
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=NEQ203;
OS   Nanoarchaeum equitans (strain Kin4-M).
OC   Archaea; Nanoarchaeota; Candidatus Nanoarchaeia; Nanoarchaeales;
OC   Nanoarchaeaceae; Nanoarchaeum.
OX   NCBI_TaxID=228908;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Kin4-M;
RX   PubMed=14566062; DOI=10.1073/pnas.1735403100;
RA   Waters E., Hohn M.J., Ahel I., Graham D.E., Adams M.D., Barnstead M.,
RA   Beeson K.Y., Bibbs L., Bolanos R., Keller M., Kretz K., Lin X., Mathur E.,
RA   Ni J., Podar M., Richardson T., Sutton G.G., Simon M., Soell D.,
RA   Stetter K.O., Short J.M., Noorderwier M.;
RT   "The genome of Nanoarchaeum equitans: insights into early archaeal
RT   evolution and derived parasitism.";
RL   Proc. Natl. Acad. Sci. U.S.A. 100:12984-12988(2003).
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; AE017199; AAR39057.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q74MP5; -.
DR   SMR; Q74MP5; -.
DR   STRING; 228908.NEQ203; -.
DR   EnsemblBacteria; AAR39057; AAR39057; NEQ203.
DR   KEGG; neq:NEQ203; -.
DR   HOGENOM; CLU_035750_7_2_2; -.
DR   OMA; VDKTGPH; -.
DR   Proteomes; UP000000578; 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   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
FT                   /note="Removed in mature form; by autocatalysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02113"
FT                   /id="PRO_0000397380"
FT   CHAIN           2..196
FT                   /note="Proteasome subunit beta"
FT                   /id="PRO_0000397381"
FT   ACT_SITE        2
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02113"
SQ   SEQUENCE   196 AA;  21435 MW;  19AD0B7323AF7290 CRC64;
     MTTIIGIKAR DGVVLASDKQ ASMGNIVEDK RAQKIIPITD YILLAGSGTV ADLQHIAKIL
     KTELKLRELY SRRTMNVIEA ANLLSHLLYQ NRFYLNPLGL LIAGPINSKE FGIYSLDGIG
     AISEIKDYFA EGSGGVIALG TLEAEYNPDI TVRDAIKLAE KALKSSIARD VFSGYGIEIY
     TITKKGVEKL FLEAQK