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Protein

Proteasome subunit beta

Gene

prcB

Organism
Mycobacterium smegmatis (strain ATCC 700084 / mc(2)155)
Status
Reviewed-Annotation score: Annotation score: 4 out of 5-Experimental evidence at protein leveli

Functioni

Component of the proteasome core, a large protease complex with broad specificity involved in protein degradation. The M.smegmatis proteasome is able to cleave oligopeptides after hydrophobic residues, thus displaying chymotrypsin-like activity. In complex with the ATPase Mpa, degrades protein targets conjugated to a prokaryotic ubiquitin-like protein (Pup). Among the identified substrates of the M.smegmatis proteasome are the pupylated SodA and Ino1 proteins (PubMed:19028679). The Pup-proteasome system (PPS) is essential for survival under starvation; PPS likely functions to recycle amino acids under nitrogen starvation, thereby enabling the cell to maintain basal metabolic activities (PubMed:24986881).UniRule annotation3 Publications

Catalytic activityi

Cleavage of peptide bonds with very broad specificity.UniRule annotation2 Publications

Enzyme regulationi

The formation of the proteasomal ATPase ARC-20S proteasome complex, likely via the docking of the C-termini of ARC into the intersubunit pockets in the alpha-rings, may trigger opening of the gate for substrate entry. Interconversion between the open-gate and close-gate conformations leads to a dynamic regulation of the 20S proteasome proteolysis activity (By similarity). PPS auto-regulates its own activity via pupylation and degradation of its components (PubMed:24986881). Peptidolytic activity is inhibited by N-acetyl-Leu-Leu-norleucinal (Ac-LLnL) in vitro (PubMed:9282749).UniRule annotation2 Publications

Pathwayi: proteasomal Pup-dependent pathway

This protein is involved in the pathway proteasomal Pup-dependent pathway, which is part of Protein degradation.UniRule annotation
View all proteins of this organism that are known to be involved in the pathway proteasomal Pup-dependent pathway and in Protein degradation.

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Active sitei63NucleophileUniRule annotation1

GO - Molecular functioni

GO - Biological processi

Keywordsi

Molecular functionHydrolase, Protease, Threonine protease

Enzyme and pathway databases

UniPathwayiUPA00997.

Protein family/group databases

MEROPSiT01.005.

Names & Taxonomyi

Protein namesi
Recommended name:
Proteasome subunit betaUniRule annotation (EC:3.4.25.1UniRule annotation)
Alternative name(s):
20S proteasome beta subunitUniRule annotation
Proteasome core protein PrcBUniRule annotation
Gene namesi
Name:prcBUniRule annotation
Ordered Locus Names:MSMEG_3895, MSMEI_3805
OrganismiMycobacterium smegmatis (strain ATCC 700084 / mc(2)155)
Taxonomic identifieri246196 [NCBI]
Taxonomic lineageiBacteriaActinobacteriaCorynebacterialesMycobacteriaceaeMycobacterium
Proteomesi
  • UP000006158 Componenti: Chromosome
  • UP000000757 Componenti: Chromosome

Subcellular locationi

  • Cytoplasm UniRule annotation

GO - Cellular componenti

Keywords - Cellular componenti

Cytoplasm, Proteasome

Pathology & Biotechi

Disruption phenotypei

Cells lacking this gene are viable and grow at the wild-type rate, but show a large reduction in the rate of degradation of the pupylated substrates (PubMed:19028679, PubMed:9282749). Cells lacking the Pup-proteasome system (pup/prcS, prcA and prcB) completely lack pupylated proteins and intact proteasomes; they grow as well as wild-type during the exponential phase, but they show reduced survival after prolonged incubation at stationary phase (17 days after inoculation) and become hypersensitive to nitrogen limitation, and, to a lesser extent, to carbon limitation (PubMed:24986881).3 Publications

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
PropeptideiPRO_00003834871 – 62Removed in mature form; by autocatalysisUniRule annotationAdd BLAST62
ChainiPRO_000038348863 – 303Proteasome subunit betaAdd BLAST241

Keywords - PTMi

Autocatalytic cleavage, Zymogen

Interactioni

Subunit structurei

The 20S proteasome core is composed of 14 alpha and 14 beta subunits that assemble into four stacked heptameric rings, resulting in a barrel-shaped structure. The two inner rings, each composed of seven catalytic beta subunits, are sandwiched by two outer rings, each composed of seven alpha subunits. The catalytic chamber with the active sites is on the inside of the barrel. Has a gated structure, the ends of the cylinder being occluded by the N-termini of the alpha-subunits. Is capped by the proteasome-associated ATPase, ARC.UniRule annotation

Protein-protein interaction databases

STRINGi246196.MSMEG_3895.

Structurei

3D structure databases

ProteinModelPortaliA0QZ47.
SMRiA0QZ47.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Belongs to the peptidase T1B family.UniRule annotation

Phylogenomic databases

eggNOGiENOG4105KPK. Bacteria.
COG0638. LUCA.
HOGENOMiHOG000245308.
KOiK03433.
OrthoDBiPOG091H08LD.

Family and domain databases

Gene3Di3.60.20.10. 1 hit.
HAMAPiMF_02113_B. Proteasome_B_B. 1 hit.
InterProiView protein in InterPro
IPR029055. Ntn_hydrolases_N.
IPR022483. Pept_T1A_Psome_suB_actinobac.
IPR001353. Proteasome_sua/b.
IPR023333. Proteasome_suB-type.
PfamiView protein in Pfam
PF00227. Proteasome. 1 hit.
SUPFAMiSSF56235. SSF56235. 1 hit.
TIGRFAMsiTIGR03690. 20S_bact_beta. 1 hit.
PROSITEiView protein in PROSITE
PS51476. PROTEASOME_BETA_2. 1 hit.

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

A0QZ47-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MTWRDNQSFP QPTLNTTGIP SVPVDLSSFS ELLSRQAPEL LPVNRVAYGT
60 70 80 90 100
TPVGPTDAVP HGTTIVALKY PGGVLIAGDR RSTQGNMIAG RDVQKVYITD
110 120 130 140 150
DYTATGIAGT AAIAVEFARL YAVELEHYEK LEGVPLTFRG KVNRLAIMVR
160 170 180 190 200
GNLGAALQGF VALPLLVGYD LDDPHPEGAG RIVSFDAAGG WNIEEEGYQS
210 220 230 240 250
VGSGSIFAKS SMKKLYSQVS DADSALKVAV EALYDAADDD SATGGPDLVR
260 270 280 290 300
GIYPTAVTIG AEGAEEVPET RIAELAREVI ESRSRTDTFG PDARRGIDAR

GDS
Length:303
Mass (Da):32,131
Last modified:September 22, 2009 - v2
Checksum:iF464A036F8CD459C
GO

Sequence cautioni

The sequence ABK70234 differs from that shown. Reason: Erroneous initiation.Curated

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF009645 Genomic DNA. Translation: AAC45614.1.
CP000480 Genomic DNA. Translation: ABK70234.1. Different initiation.
CP001663 Genomic DNA. Translation: AFP40263.1.
RefSeqiYP_888185.1. NC_008596.1.

Genome annotation databases

EnsemblBacteriaiABK70234; ABK70234; MSMEG_3895.
AFP40263; AFP40263; MSMEI_3805.
GeneIDi4534165.
KEGGimsg:MSMEI_3805.
msm:MSMEG_3895.
PATRICifig|246196.19.peg.3835.

Similar proteinsi

Entry informationi

Entry nameiPSB_MYCS2
AccessioniPrimary (citable) accession number: A0QZ47
Secondary accession number(s): I7FNI5, O30518
Entry historyiIntegrated into UniProtKB/Swiss-Prot: September 22, 2009
Last sequence update: September 22, 2009
Last modified: August 30, 2017
This is version 82 of the entry and version 2 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. PATHWAY comments
    Index of metabolic and biosynthesis pathways
  2. Peptidase families
    Classification of peptidase families and list of entries
  3. SIMILARITY comments
    Index of protein domains and families