ID   PSB_MYCS2               Reviewed;         303 AA.
AC   A0QZ47; I7FNI5; O30518;
DT   22-SEP-2009, integrated into UniProtKB/Swiss-Prot.
DT   22-SEP-2009, sequence version 2.
DT   24-JAN-2024, entry version 106.
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 PrcB {ECO:0000255|HAMAP-Rule:MF_02113};
DE   Flags: Precursor;
GN   Name=prcB {ECO:0000255|HAMAP-Rule:MF_02113};
GN   OrderedLocusNames=MSMEG_3895, MSMEI_3805;
OS   Mycolicibacterium smegmatis (strain ATCC 700084 / mc(2)155) (Mycobacterium
OS   smegmatis).
OC   Bacteria; Actinomycetota; Actinomycetes; Mycobacteriales; Mycobacteriaceae;
OC   Mycolicibacterium.
OX   NCBI_TaxID=246196;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, CATALYTIC ACTIVITY, ACTIVITY
RP   REGULATION, AND DISRUPTION PHENOTYPE.
RX   PubMed=9282749; DOI=10.1046/j.1365-2958.1997.4721837.x;
RA   Knipfer N., Shrader T.E.;
RT   "Inactivation of the 20S proteasome in Mycobacterium smegmatis.";
RL   Mol. Microbiol. 25:375-383(1997).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 700084 / mc(2)155;
RA   Fleischmann R.D., Dodson R.J., Haft D.H., Merkel J.S., Nelson W.C.,
RA   Fraser C.M.;
RL   Submitted (OCT-2006) to the EMBL/GenBank/DDBJ databases.
RN   [3]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 700084 / mc(2)155;
RX   PubMed=17295914; DOI=10.1186/gb-2007-8-2-r20;
RA   Deshayes C., Perrodou E., Gallien S., Euphrasie D., Schaeffer C.,
RA   Van-Dorsselaer A., Poch O., Lecompte O., Reyrat J.-M.;
RT   "Interrupted coding sequences in Mycobacterium smegmatis: authentic
RT   mutations or sequencing errors?";
RL   Genome Biol. 8:R20.1-R20.9(2007).
RN   [4]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 700084 / mc(2)155;
RX   PubMed=18955433; DOI=10.1101/gr.081901.108;
RA   Gallien S., Perrodou E., Carapito C., Deshayes C., Reyrat J.-M.,
RA   Van Dorsselaer A., Poch O., Schaeffer C., Lecompte O.;
RT   "Ortho-proteogenomics: multiple proteomes investigation through orthology
RT   and a new MS-based protocol.";
RL   Genome Res. 19:128-135(2009).
RN   [5]
RP   FUNCTION, CATALYTIC ACTIVITY, PROTEIN SUBSTRATES, AND DISRUPTION PHENOTYPE.
RX   PubMed=19028679; DOI=10.1074/jbc.m808032200;
RA   Burns K.E., Liu W.-T., Boshoff H.I.M., Dorrestein P.C., Barry C.E. III;
RT   "Proteasomal protein degradation in mycobacteria is dependent upon a
RT   prokaryotic ubiquitin-like protein.";
RL   J. Biol. Chem. 284:3069-3075(2009).
RN   [6]
RP   FUNCTION, DISRUPTION PHENOTYPE, AND ACTIVITY REGULATION.
RC   STRAIN=ATCC 700084 / mc(2)155;
RX   PubMed=24986881; DOI=10.15252/embj.201387076;
RA   Elharar Y., Roth Z., Hermelin I., Moon A., Peretz G., Shenkerman Y.,
RA   Vishkautzan M., Khalaila I., Gur E.;
RT   "Survival of mycobacteria depends on proteasome-mediated amino acid
RT   recycling under nutrient limitation.";
RL   EMBO J. 33:1802-1814(2014).
CC   -!- FUNCTION: Component of the proteasome core, a large protease complex
CC       with broad specificity involved in protein degradation. The M.smegmatis
CC       proteasome is able to cleave oligopeptides after hydrophobic residues,
CC       thus displaying chymotrypsin-like activity. In complex with the ATPase
CC       Mpa, degrades protein targets conjugated to a prokaryotic ubiquitin-
CC       like protein (Pup). Among the identified substrates of the M.smegmatis
CC       proteasome are the pupylated SodA and Ino1 proteins (PubMed:19028679).
CC       The Pup-proteasome system (PPS) is essential for survival under
CC       starvation; PPS likely functions to recycle amino acids under nitrogen
CC       starvation, thereby enabling the cell to maintain basal metabolic
CC       activities (PubMed:24986881). {ECO:0000255|HAMAP-Rule:MF_02113,
CC       ECO:0000269|PubMed:19028679, ECO:0000269|PubMed:24986881,
CC       ECO:0000269|PubMed:9282749}.
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:19028679, ECO:0000269|PubMed:9282749};
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 (By similarity). PPS auto-regulates its
CC       own activity via pupylation and degradation of its components
CC       (PubMed:24986881). Peptidolytic activity is inhibited by N-acetyl-Leu-
CC       Leu-norleucinal (Ac-LLnL) in vitro (PubMed:9282749).
CC       {ECO:0000255|HAMAP-Rule:MF_02113, ECO:0000269|PubMed:24986881,
CC       ECO:0000269|PubMed:9282749}.
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. 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 by the proteasome-associated ATPase, ARC. {ECO:0000255|HAMAP-
CC       Rule:MF_02113}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_02113}.
CC   -!- DISRUPTION PHENOTYPE: Cells lacking this gene are viable and grow at
CC       the wild-type rate, but show a large reduction in the rate of
CC       degradation of the pupylated substrates (PubMed:19028679,
CC       PubMed:9282749). Cells lacking the Pup-proteasome system (pup/prcS,
CC       prcA and prcB) completely lack pupylated proteins and intact
CC       proteasomes; they grow as well as wild-type during the exponential
CC       phase, but they show reduced survival after prolonged incubation at
CC       stationary phase (17 days after inoculation) and become hypersensitive
CC       to nitrogen limitation, and, to a lesser extent, to carbon limitation
CC       (PubMed:24986881). {ECO:0000269|PubMed:19028679,
CC       ECO:0000269|PubMed:24986881, ECO:0000269|PubMed:9282749}.
CC   -!- SIMILARITY: Belongs to the peptidase T1B family. {ECO:0000255|HAMAP-
CC       Rule:MF_02113}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=ABK70234.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; AF009645; AAC45614.1; -; Genomic_DNA.
DR   EMBL; CP000480; ABK70234.1; ALT_INIT; Genomic_DNA.
DR   EMBL; CP001663; AFP40263.1; -; Genomic_DNA.
DR   RefSeq; YP_888185.1; NC_008596.1.
DR   AlphaFoldDB; A0QZ47; -.
DR   SMR; A0QZ47; -.
DR   STRING; 246196.MSMEG_3895; -.
DR   MEROPS; T01.005; -.
DR   PaxDb; 246196-MSMEI_3805; -.
DR   KEGG; msg:MSMEI_3805; -.
DR   KEGG; msm:MSMEG_3895; -.
DR   PATRIC; fig|246196.19.peg.3835; -.
DR   eggNOG; COG0638; Bacteria.
DR   OrthoDB; 5174038at2; -.
DR   UniPathway; UPA00997; -.
DR   Proteomes; UP000000757; Chromosome.
DR   Proteomes; UP000006158; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0019774; C:proteasome core complex, beta-subunit complex; ISS: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; IEA:UniProtKB-UniRule.
DR   CDD; cd01906; proteasome_protease_HslV; 1.
DR   Gene3D; 3.60.20.10; Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1; 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   NCBIfam; TIGR03690; 20S_bact_beta; 1.
DR   PANTHER; PTHR32194:SF0; ATP-DEPENDENT PROTEASE SUBUNIT HSLV; 1.
DR   PANTHER; PTHR32194; METALLOPROTEASE TLDD; 1.
DR   Pfam; PF00227; Proteasome; 1.
DR   SUPFAM; SSF56235; N-terminal nucleophile aminohydrolases (Ntn hydrolases); 1.
DR   PROSITE; PS51476; PROTEASOME_BETA_2; 1.
PE   1: Evidence at protein level;
KW   Autocatalytic cleavage; Cytoplasm; Hydrolase; Protease; Proteasome;
KW   Reference proteome; Threonine protease; Zymogen.
FT   PROPEP          1..62
FT                   /note="Removed in mature form; by autocatalysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02113"
FT                   /id="PRO_0000383487"
FT   CHAIN           63..303
FT                   /note="Proteasome subunit beta"
FT                   /id="PRO_0000383488"
FT   REGION          282..303
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        63
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_02113"
SQ   SEQUENCE   303 AA;  32131 MW;  F464A036F8CD459C CRC64;
     MTWRDNQSFP QPTLNTTGIP SVPVDLSSFS ELLSRQAPEL LPVNRVAYGT TPVGPTDAVP
     HGTTIVALKY PGGVLIAGDR RSTQGNMIAG RDVQKVYITD DYTATGIAGT AAIAVEFARL
     YAVELEHYEK LEGVPLTFRG KVNRLAIMVR GNLGAALQGF VALPLLVGYD LDDPHPEGAG
     RIVSFDAAGG WNIEEEGYQS VGSGSIFAKS SMKKLYSQVS DADSALKVAV EALYDAADDD
     SATGGPDLVR GIYPTAVTIG AEGAEEVPET RIAELAREVI ESRSRTDTFG PDARRGIDAR
     GDS
//