ID   PSB1_ENCCU              Reviewed;         203 AA.
AC   Q8SR11;
DT   01-SEP-2009, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-2002, sequence version 1.
DT   25-MAY-2022, entry version 104.
DE   RecName: Full=Probable proteasome subunit beta type-1;
DE            EC=3.4.25.1;
DE   AltName: Full=26S proteasome beta-type subunit PRE3;
DE   AltName: Full=Multicatalytic endopeptidase complex subunit PRE3;
DE   Flags: Precursor;
GN   Name=PRE3; OrderedLocusNames=ECU10_1450;
OS   Encephalitozoon cuniculi (strain GB-M1) (Microsporidian parasite).
OC   Eukaryota; Fungi; Fungi incertae sedis; Microsporidia; Unikaryonidae;
OC   Encephalitozoon.
OX   NCBI_TaxID=284813;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=GB-M1;
RX   PubMed=11719806; DOI=10.1038/35106579;
RA   Katinka M.D., Duprat S., Cornillot E., Metenier G., Thomarat F.,
RA   Prensier G., Barbe V., Peyretaillade E., Brottier P., Wincker P.,
RA   Delbac F., El Alaoui H., Peyret P., Saurin W., Gouy M., Weissenbach J.,
RA   Vivares C.P.;
RT   "Genome sequence and gene compaction of the eukaryote parasite
RT   Encephalitozoon cuniculi.";
RL   Nature 414:450-453(2001).
RN   [2]
RP   IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS], AND
RP   DEVELOPMENTAL STAGE.
RX   PubMed=16691553; DOI=10.1002/pmic.200500796;
RA   Brosson D., Kuhn L., Delbac F., Garin J., Vivares C.P., Texier C.;
RT   "Proteomic analysis of the eukaryotic parasite Encephalitozoon cuniculi
RT   (microsporidia): a reference map for proteins expressed in late sporogonial
RT   stages.";
RL   Proteomics 6:3625-3635(2006).
CC   -!- FUNCTION: The proteasome degrades poly-ubiquitinated proteins in the
CC       cytoplasm and in the nucleus. It is essential for the regulated
CC       turnover of proteins and for the removal of misfolded proteins. The
CC       proteasome is a multicatalytic proteinase complex that is characterized
CC       by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu
CC       adjacent to the leaving group at neutral or slightly basic pH. It has
CC       an ATP-dependent proteolytic activity (By similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Cleavage of peptide bonds with very broad specificity.;
CC         EC=3.4.25.1;
CC   -!- SUBUNIT: The 26S proteasome consists of a 20S proteasome core and two
CC       19S regulatory subunits. The 20S proteasome core is composed of 28
CC       subunits that are arranged in four stacked rings, resulting in a
CC       barrel-shaped structure. The two end rings are each formed by seven
CC       alpha subunits, and the two central rings are each formed by seven beta
CC       subunits. The catalytic chamber with the active sites is on the inside
CC       of the barrel (By similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|PROSITE-ProRule:PRU00809}.
CC       Nucleus {ECO:0000250}.
CC   -!- DEVELOPMENTAL STAGE: Expressed in late sporogonial stages.
CC       {ECO:0000269|PubMed:16691553}.
CC   -!- SIMILARITY: Belongs to the peptidase T1B family. {ECO:0000255|PROSITE-
CC       ProRule:PRU00809}.
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DR   EMBL; AL590449; CAD25864.1; -; Genomic_DNA.
DR   RefSeq; NP_586260.1; NM_001042093.1.
DR   AlphaFoldDB; Q8SR11; -.
DR   SMR; Q8SR11; -.
DR   STRING; 284813.Q8SR11; -.
DR   MEROPS; T01.010; -.
DR   GeneID; 859910; -.
DR   KEGG; ecu:ECU10_1450; -.
DR   VEuPathDB; MicrosporidiaDB:ECU10_1450; -.
DR   HOGENOM; CLU_035750_5_2_1; -.
DR   InParanoid; Q8SR11; -.
DR   OMA; HKQAYAI; -.
DR   OrthoDB; 1172133at2759; -.
DR   Proteomes; UP000000819; Chromosome X.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0005634; C:nucleus; 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-KW.
DR   GO; GO:0043161; P:proteasome-mediated ubiquitin-dependent protein catabolic process; IEA:InterPro.
DR   Gene3D; 3.60.20.10; -; 1.
DR   InterPro; IPR029055; Ntn_hydrolases_N.
DR   InterPro; IPR000243; Pept_T1A_subB.
DR   InterPro; IPR037559; Proteasome_beta_Pre3.
DR   InterPro; IPR016050; Proteasome_bsu_CS.
DR   InterPro; IPR001353; Proteasome_sua/b.
DR   InterPro; IPR023333; Proteasome_suB-type.
DR   PANTHER; PTHR11599:SF4; PTHR11599:SF4; 1.
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   1: Evidence at protein level;
KW   Cytoplasm; Hydrolase; Nucleus; Protease; Proteasome; Reference proteome;
KW   Threonine protease.
FT   PROPEP          1..10
FT                   /note="Removed in mature form"
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000391408"
FT   CHAIN           11..203
FT                   /note="Probable proteasome subunit beta type-1"
FT                   /id="PRO_0000382760"
FT   ACT_SITE        11
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   203 AA;  22189 MW;  DC82D2EAD817DA3E CRC64;
     MMSNEKEMTG TTIIAIKYDD GVLIGADSRT SMGAYVSSRV TDKLTQITDK IFVCRSGSSA
     DTQMISSYLR MYLSMYSQLE DSIPQVQRAA ALASKIIYEN PSLLAGLIVA GYDDKPRVFN
     ISLGGSLTER DWAIGGSGSA FIYGYCDVNW RSGMSLEEGI RFVRNAVSCA INRDNASGGC
     IRMSAISRTG VQRYFYPGDK VLQ