ID   PSB2_RHOER              Reviewed;         292 AA.
AC   Q53083;
DT   10-AUG-2010, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   25-MAY-2022, entry version 86.
DE   RecName: Full=Proteasome subunit beta 2 {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 2 {ECO:0000255|HAMAP-Rule:MF_02113};
DE   AltName: Full=Proteasome core protein PrcB 2 {ECO:0000255|HAMAP-Rule:MF_02113};
DE   Flags: Precursor;
GN   Name=prcB2 {ECO:0000255|HAMAP-Rule:MF_02113};
OS   Rhodococcus erythropolis (Arthrobacter picolinophilus).
OC   Bacteria; Actinobacteria; Corynebacteriales; Nocardiaceae; Rhodococcus;
OC   Rhodococcus erythropolis group.
OX   NCBI_TaxID=1833;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 60-92; 139-156;
RP   211-228 AND 269-292, FUNCTION, CATALYTIC ACTIVITY, SUBSTRATE SPECIFICITY,
RP   AND SUBUNIT.
RC   STRAIN=NI86/21;
RX   PubMed=7583123; DOI=10.1016/s0960-9822(95)00153-9;
RA   Tamura T., Nagy I., Lupas A., Lottspeich F., Cejka Z., Schoofs G.,
RA   Tanaka K., de Mot R., Baumeister W.;
RT   "The first characterization of a eubacterial proteasome: the 20S complex of
RT   Rhodococcus.";
RL   Curr. Biol. 5:766-774(1995).
RN   [2]
RP   SUBUNIT, FUNCTION, CATALYTIC ACTIVITY, SUBSTRATE SPECIFICITY, AND KINETIC
RP   PARAMETERS.
RC   STRAIN=NI86/21;
RX   PubMed=9000518; DOI=10.1016/s0014-5793(96)01403-2;
RA   Zuhl F., Tamura T., Dolenc I., Cejka Z., Nagy I., De Mot R., Baumeister W.;
RT   "Subunit topology of the Rhodococcus proteasome.";
RL   FEBS Lett. 400:83-90(1997).
CC   -!- FUNCTION: Component of the proteasome core, a large protease complex
CC       with broad specificity involved in protein degradation. The
CC       R.erythropolis proteasomes are able to cleave oligopeptides after Tyr,
CC       Phe and Leu, very poorly after Arg but not after Glu. Thus, displays
CC       chymotrypsin-like activity, low trypsin-like activity but no caspase-
CC       like activity. {ECO:0000255|HAMAP-Rule:MF_02113,
CC       ECO:0000269|PubMed:7583123, ECO:0000269|PubMed:9000518}.
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         ECO:0000269|PubMed:7583123, ECO:0000269|PubMed:9000518};
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. {ECO:0000255|HAMAP-Rule:MF_02113}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=61.4 uM for Suc-Leu-Leu-Val-Tyr-AMC (with the beta2-alpha1
CC         proteasome subtype) {ECO:0000269|PubMed:9000518};
CC         KM=66.4 uM for Suc-Leu-Leu-Val-Tyr-AMC (with the beta2-alpha2
CC         proteasome subtype) {ECO:0000269|PubMed:9000518};
CC         KM=71.2 uM for Suc-Leu-Leu-Val-Tyr-AMC (with the beta1-alpha2
CC         proteasome subtype) {ECO:0000269|PubMed:9000518};
CC         KM=84.3 uM for Suc-Leu-Leu-Val-Tyr-AMC (with the beta1-alpha1
CC         proteasome subtype) {ECO:0000269|PubMed:9000518};
CC         Note=The Vmax observed with the beta2-alpha1 proteasome subtype is
CC         2.2-fold, 1.2-fold and 4-fold higher than that with the beta2-alpha2,
CC         beta1-alpha2 and beta1-alpha1 subtypes, respectively.;
CC   -!- PATHWAY: Protein degradation; proteasomal Pup-dependent pathway.
CC       {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. All four combinations of alpha- and
CC       beta-subunits (beta2-alpha1, beta2-alpha2, beta1-alpha2 and beta1-
CC       alpha1) yield fully assembled and proteolytically active proteasomes.
CC       The catalytic chamber with the active sites is on the inside of the
CC       barrel. Has probably a gated structure, the ends of the cylinder being
CC       occluded by the N-termini of the alpha-subunits. Is likely capped by
CC       the proteasome-associated ATPase, ARC. {ECO:0000269|PubMed:7583123,
CC       ECO:0000269|PubMed:9000518}.
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; U26422; AAC45736.1; -; Genomic_DNA.
DR   RefSeq; WP_019748515.1; NZ_UGVH01000001.1.
DR   AlphaFoldDB; Q53083; -.
DR   SMR; Q53083; -.
DR   STRING; 1833.XU06_14800; -.
DR   MEROPS; T01.005; -.
DR   GeneID; 57486888; -.
DR   OMA; NLGMAMQ; -.
DR   UniPathway; UPA00997; -.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0019774; C:proteasome core complex, beta-subunit complex; IDA:UniProtKB.
DR   GO; GO:0004175; F:endopeptidase activity; IDA:UniProtKB.
DR   GO; GO:0004298; F:threonine-type endopeptidase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0019941; P:modification-dependent protein catabolic process; IEA:UniProtKB-UniRule.
DR   GO; GO:0010498; P:proteasomal protein catabolic process; IDA:UniProtKB.
DR   Gene3D; 3.60.20.10; -; 1.
DR   HAMAP; MF_02113_B; Proteasome_B_B; 1.
DR   InterPro; IPR029055; Ntn_hydrolases_N.
DR   InterPro; IPR001353; Proteasome_sua/b.
DR   InterPro; IPR023333; Proteasome_suB-type.
DR   InterPro; IPR022483; PSB_actinobac.
DR   Pfam; PF00227; Proteasome; 1.
DR   SUPFAM; SSF56235; SSF56235; 1.
DR   TIGRFAMs; TIGR03690; 20S_bact_beta; 1.
DR   PROSITE; PS51476; PROTEASOME_BETA_2; 1.
PE   1: Evidence at protein level;
KW   Autocatalytic cleavage; Cytoplasm; Direct protein sequencing; Hydrolase;
KW   Protease; Proteasome; Threonine protease; Zymogen.
FT   PROPEP          1..59
FT                   /note="Removed in mature form; by autocatalysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02113,
FT                   ECO:0000269|PubMed:7583123"
FT                   /id="PRO_0000397126"
FT   CHAIN           60..292
FT                   /note="Proteasome subunit beta 2"
FT                   /id="PRO_0000397127"
FT   ACT_SITE        60
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02113"
SQ   SEQUENCE   292 AA;  30398 MW;  759E364233C73FBE CRC64;
     MTVDRAPRIT DGDTRLSFGS NLSSFSEYLR VHAPEHLPQN RFADTGGVVM GGGDVAPHGT
     TIVAISYAGG VLLAGDRRAT MGNLIASRDV QKVYVTDDYS AAGIAGTAGI AIELVRLFAV
     ELEHYEKIEG VPLTFDGKAN RLSSMVRGNL GAAMQGLAVV PLLVGYDLDA VDPSRAGRIV
     SYDVVGGRYE ERAGYHAVGS GSLFAKSALK KLYSPGIDED TALRFAVEAL YDAADDDSAT
     GGPDLTRGIY PTAVTITSAG AVELSTAKAA EIAREIVAAR TATASPEGES AL