D4GYZ1 (PSB_HALVD) Reviewed, UniProtKB/Swiss-Prot
Last modified June 11, 2014. Version 28. History...
Names and origin
|Protein names||Recommended name:|
Proteasome subunit beta
20S proteasome beta subunit
Proteasome core protein PsmB
|Organism||Haloferax volcanii (strain ATCC 29605 / DSM 3757 / JCM 8879 / NBRC 14742 / NCIMB 2012 / VKM B-1768 / DS2) (Halobacterium volcanii) [Reference proteome] [HAMAP]|
|Taxonomic identifier||309800 [NCBI]|
|Taxonomic lineage||Archaea › Euryarchaeota › Halobacteria › Halobacteriales › Halobacteriaceae › Haloferax ›|
|Sequence length||243 AA.|
|Sequence processing||The displayed sequence is further processed into a mature form.|
|Protein existence||Evidence at protein level|
General annotation (Comments)
Component of the proteasome core, a large protease complex with broad specificity involved in protein degradation. The H.volcanii alpha1-beta proteasome is able to cleave oligopeptides after Phe, Tyr and Trp, poorly after Glu but not after Arg. Thus, displays chymotrypsin-like activity, low caspase-like activity but no trypsin-like activity. Ref.1
Cleavage of peptide bonds with very broad specificity. Ref.1
The formation of the proteasomal ATPase PAN-20S proteasome complex, via the docking of the C-termini of PAN into the intersubunit pockets in the alpha-rings, triggers 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. In vitro, the chymotrypsin-like activity of the alpha1-beta proteasome is potently inhibited by carbobenzoxyl-leucinyl-leucinyl-leucinal-H (MG132) and significantly by N-acetyl-leucinyl-leucinyl-norleucinal-H (calpain inhibitor I). Ref.1
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. H.volcanii produces at least 2 types of 20S proteasomes: an alpha1-beta proteasome and a proteasome containing all three subunits (alpha1, alpha2, and beta) that appears to be asymmetrical with homo-oligomeric alpha1 and alpha2 rings positioned on separate ends. The catalytic chamber with the active sites is on the inside of the barrel. Has probably a gated structure, the ends of the cylinder being occluded by the N-termini of the alpha-subunits. Is likely capped at one or both ends by the proteasome regulatory ATPase, PAN. Ref.1 Ref.3
Up-regulated at the mRNA level during transition from exponential to stationary phase. However, at the protein level, PsmB is expressed at a high and relatively constant level throughout growth. Ref.1 Ref.4
Strains lacking psmB gene are inviable. Ref.6
H.volcanii proteasome requires high concentrations of salt, similar to the extracellular environment and cytoplasm of this organism, for complex stability and optimal activity.
Belongs to the peptidase T1B family.
Optimum pH is 7.0-9.3 for the Suc-LLVY-Amc hydrolyzing activity (with the alpha1-beta proteasome subtype). Ref.1
Optimum temperature is 75 degrees Celsius for the Suc-LLVY-Amc hydrolyzing activity (with the alpha1-beta proteasome subtype).
|Technical term||Complete proteome|
Direct protein sequencing
|Gene Ontology (GO)|
|Biological_process||proteasomal protein catabolic process|
Inferred from electronic annotation. Source: UniProtKB-SubCellproteasome core complex, beta-subunit complex
|Molecular_function||endopeptidase activitythreonine-type endopeptidase activity|
Inferred from electronic annotation. Source: UniProtKB-HAMAP
|Complete GO annotation...|
Sequence annotation (Features)
|Feature key||Position(s)||Length||Description||Graphical view||Feature identifier|
|Propeptide||1 – 49||49||Removed in mature form; by autocatalysis HAMAP-Rule MF_02113||PRO_0000397605|
|Chain||50 – 243||194||Proteasome subunit beta HAMAP-Rule MF_02113||PRO_0000397606|
|Active site||50||1||Nucleophile By similarity|
Amino acid modifications
|Modified residue||129||1||Phosphoserine Ref.5|
|||"Halophilic 20S proteasomes of the archaeon Haloferax volcanii: purification, characterization, and gene sequence analysis."|
Wilson H.L., Aldrich H.C., Maupin-Furlow J.
J. Bacteriol. 181:5814-5824(1999) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 50-79, FUNCTION, CATALYTIC ACTIVITY, SUBSTRATE SPECIFICITY, BIOPHYSICOCHEMICAL PROPERTIES, ENZYME REGULATION, SALT REQUIREMENT, SUBUNIT.
|||"The complete genome sequence of Haloferax volcanii DS2, a model archaeon."|
Hartman A.L., Norais C., Badger J.H., Delmas S., Haldenby S., Madupu R., Robinson J., Khouri H., Ren Q., Lowe T.M., Maupin-Furlow J., Pohlschroder M., Daniels C., Pfeiffer F., Allers T., Eisen J.A.
PLoS ONE 5:E9605-E9605(2010) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: ATCC 29605 / DSM 3757 / JCM 8879 / NBRC 14742 / NCIMB 2012 / VKM B-1768 / DS2.
|||"Subunit topology of two 20S proteasomes from Haloferax volcanii."|
Kaczowka S.J., Maupin-Furlow J.A.
J. Bacteriol. 185:165-174(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: SUBUNIT.
|||"Differential regulation of the PanA and PanB proteasome-activating nucleotidase and 20S proteasomal proteins of the haloarchaeon Haloferax volcanii."|
Reuter C.J., Kaczowka S.J., Maupin-Furlow J.A.
J. Bacteriol. 186:7763-7772(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: INDUCTION.
|||"Posttranslational modification of the 20S proteasomal proteins of the archaeon Haloferax volcanii."|
Humbard M.A., Stevens S.M. Jr., Maupin-Furlow J.A.
J. Bacteriol. 188:7521-7530(2006) [PubMed] [Europe PMC] [Abstract]
Cited for: PHOSPHORYLATION AT SER-129.
|||"Proteasomal components required for cell growth and stress responses in the haloarchaeon Haloferax volcanii."|
Zhou G., Kowalczyk D., Humbard M.A., Rohatgi S., Maupin-Furlow J.A.
J. Bacteriol. 190:8096-8105(2008) [PubMed] [Europe PMC] [Abstract]
Cited for: DISRUPTION PHENOTYPE.
|AF126262 Genomic DNA. Translation: AAD53406.1.|
CP001956 Genomic DNA. Translation: ADE03141.1.
|RefSeq||YP_003535609.1. NC_013967.1. |
3D structure databases
Protein family/group databases
Protocols and materials databases
Genome annotation databases
|EnsemblBacteria||ADE03141; ADE03141; HVO_1562. |
Enzyme and pathway databases
Family and domain databases
|Gene3D||18.104.22.168. 1 hit. |
|HAMAP||MF_02113_A. Proteasome_B_A. |
|InterPro||IPR029055. Ntn_hydrolases_N. |
|Pfam||PF00227. Proteasome. 1 hit. |
|PRINTS||PR00141. PROTEASOME. |
|SUPFAM||SSF56235. SSF56235. 1 hit. |
|TIGRFAMs||TIGR03634. arc_protsome_B. 1 hit. |
|PROSITE||PS51476. PROTEASOME_BETA_2. 1 hit. |
|Accession||Primary (citable) accession number: D4GYZ1|
Secondary accession number(s): Q9V2V4
|Entry status||Reviewed (UniProtKB/Swiss-Prot)|
|Annotation program||Prokaryotic Protein Annotation Program|