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Protein

Proteasome subunit alpha 1

Gene

psmA1

Organism
Haloferax volcanii (strain ATCC 29605 / DSM 3757 / JCM 8879 / NBRC 14742 / NCIMB 2012 / VKM B-1768 / DS2) (Halobacterium volcanii)
Status
Reviewed-Annotation score: Annotation score: 5 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 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.UniRule annotation1 Publication

Catalytic activityi

Cleavage of peptide bonds with very broad specificity.UniRule annotation1 Publication

Enzyme regulationi

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).UniRule annotation1 Publication

pH dependencei

Optimum pH is 7.0-9.3 for the Suc-LLVY-Amc hydrolyzing activity (with the alpha1-beta proteasome subtype).1 Publication

Temperature dependencei

Optimum temperature is 75 degrees Celsius for the Suc-LLVY-Amc hydrolyzing activity (with the alpha1-beta proteasome subtype).1 Publication

GO - Molecular functioni

  1. endopeptidase activity Source: UniProtKB
  2. threonine-type endopeptidase activity Source: UniProtKB-HAMAP

GO - Biological processi

  1. proteasomal protein catabolic process Source: UniProtKB
  2. ubiquitin-dependent protein catabolic process Source: InterPro
Complete GO annotation...

Keywords - Molecular functioni

Hydrolase, Protease, Threonine protease

Enzyme and pathway databases

BioCyciHVOL309800:GCOK-1095-MONOMER.

Names & Taxonomyi

Protein namesi
Recommended name:
Proteasome subunit alpha 1UniRule annotation (EC:3.4.25.1UniRule annotation)
Alternative name(s):
20S proteasome alpha subunit 1UniRule annotation
Proteasome core protein PsmA 1UniRule annotation
Cleaved into the following chain:
Proteasome subunit alpha 1, N-terminally processedUniRule annotation
Gene namesi
Name:psmA1UniRule annotation
Synonyms:psmA
Ordered Locus Names:HVO_1091
OrganismiHaloferax volcanii (strain ATCC 29605 / DSM 3757 / JCM 8879 / NBRC 14742 / NCIMB 2012 / VKM B-1768 / DS2) (Halobacterium volcanii)
Taxonomic identifieri309800 [NCBI]
Taxonomic lineageiArchaeaEuryarchaeotaHalobacteriaHalobacterialesHalobacteriaceaeHaloferax
ProteomesiUP000008243 Componenti: Chromosome

Subcellular locationi

Cytoplasm UniRule annotation

GO - Cellular componenti

  1. cytoplasm Source: UniProtKB-SubCell
  2. proteasome core complex, alpha-subunit complex Source: UniProtKB
Complete GO annotation...

Keywords - Cellular componenti

Cytoplasm, Proteasome

Pathology & Biotechi

Disruption phenotypei

Strains lacking psmA1 gene alone display relatively normal growth rate and overall cell yield, but they are more sensitive to growth on organic versus inorganic nitrogen sources and hypo-osmotic stress, and they show limited growth in the presence of L-canavanine. Abolition of alpha1 subunit synthesis also has a severe impact on the ability of cells to withstand thermal stress. Moreover, depletion of psmA1 and psmA2 together renders the cells inviable.1 Publication

Mutagenesis

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Mutagenesisi2 – 1211Missing : Prevents acetylation of Met-1. Enhances peptidase activity of the proteasome. Renders the cells less tolerant of hypoosmotic stress than the wild-type. 1 PublicationAdd
BLAST
Mutagenesisi2 – 21Q → A: Enhances cleavage of PsmA1 by methionine aminopeptidase (MAP), resulting in acetylation of the N-terminal alanine. Enhances peptidase activity of the proteasome. Renders the cells less tolerant of hypoosmotic stress than the wild-type. 1 Publication
Mutagenesisi2 – 21Q → D, P or T: Does not alter the prevalence of the alpha1 subunit in N-acetylated form in proteasomes. Renders the cells more tolerant of hypoosmotic and high-temperature stress than the wild-type. 1 Publication

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 252252Proteasome subunit alpha 1PRO_0000124171Add
BLAST
Initiator methioninei1 – 11Removed; alternate1 Publication
Chaini2 – 252251Proteasome subunit alpha 1, N-terminally processedPRO_0000397604Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei1 – 11N-acetylmethionine; alternate1 Publication

Post-translational modificationi

Acetylated. The acetylated form at Met-1 was shown to be in 100-fold excess of the unacetylated form with the initiator methionine removed in whole cells and purified 20S proteasomes.2 Publications

Keywords - PTMi

Acetylation

Expressioni

Inductioni

Up-regulated at the mRNA level during transition from exponential to stationary phase. However, at the protein level, PsmA 1 is expressed at a high and relatively constant level throughout growth.1 Publication

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. 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.2 Publications

Family & Domainsi

Sequence similaritiesi

Belongs to the peptidase T1A family.UniRule annotation

Phylogenomic databases

HOGENOMiHOG000091085.
KOiK03432.
OMAiSGAYFEW.

Family and domain databases

Gene3Di3.60.20.10. 1 hit.
HAMAPiMF_00289_A. Proteasome_A_A.
InterProiIPR029055. Ntn_hydrolases_N.
IPR019982. Proteasome_asu_arc.
IPR000426. Proteasome_asu_N.
IPR023332. Proteasome_suA-type.
IPR001353. Proteasome_sua/b.
[Graphical view]
PfamiPF00227. Proteasome. 1 hit.
PF10584. Proteasome_A_N. 1 hit.
[Graphical view]
SMARTiSM00948. Proteasome_A_N. 1 hit.
[Graphical view]
SUPFAMiSSF56235. SSF56235. 1 hit.
TIGRFAMsiTIGR03633. arc_protsome_A. 1 hit.
PROSITEiPS00388. PROTEASOME_ALPHA_1. 1 hit.
PS51475. PROTEASOME_ALPHA_2. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

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

Q9V2V6-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MQGQAQQQAY DRGITIFSPD GRLYQVEYAR EAVKRGTASI GVRTPEGVVL
60 70 80 90 100
AADKRSRSPL MEPTSVEKIH KADDHIGIAS AGHVADARQL IDFARRQSQV
110 120 130 140 150
NRLRYGEPIG IETLTKEVTD HIQQYTQVGG ARPFGVALLI GGVENGTPRL
160 170 180 190 200
YETDPSGTPY EWKAVSIGAD RGDHQEHLEE NFRDDLTLDE GIELALEAIA
210 220 230 240 250
STSDEGTAPD GVDVATVSAE TERFVELSND EIESYLEAND LLATEDDEQT

EE
Length:252
Mass (Da):27,613
Last modified:July 12, 2010 - v2
Checksum:i500A2DCCB0B71C71
GO

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti96 – 961R → H in AAD53404 (PubMed:10482525).Curated

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF126260 Genomic DNA. Translation: AAD53404.1.
CP001956 Genomic DNA. Translation: ADE04430.1.
PIRiT48678.
RefSeqiWP_004043847.1. NZ_AOHU01000092.1.
YP_003535146.1. NC_013967.1.

Genome annotation databases

EnsemblBacteriaiADE04430; ADE04430; HVO_1091.
GeneIDi8925549.
KEGGihvo:HVO_1091.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF126260 Genomic DNA. Translation: AAD53404.1.
CP001956 Genomic DNA. Translation: ADE04430.1.
PIRiT48678.
RefSeqiWP_004043847.1. NZ_AOHU01000092.1.
YP_003535146.1. NC_013967.1.

3D structure databases

ModBaseiSearch...
MobiDBiSearch...

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaiADE04430; ADE04430; HVO_1091.
GeneIDi8925549.
KEGGihvo:HVO_1091.

Phylogenomic databases

HOGENOMiHOG000091085.
KOiK03432.
OMAiSGAYFEW.

Enzyme and pathway databases

BioCyciHVOL309800:GCOK-1095-MONOMER.

Family and domain databases

Gene3Di3.60.20.10. 1 hit.
HAMAPiMF_00289_A. Proteasome_A_A.
InterProiIPR029055. Ntn_hydrolases_N.
IPR019982. Proteasome_asu_arc.
IPR000426. Proteasome_asu_N.
IPR023332. Proteasome_suA-type.
IPR001353. Proteasome_sua/b.
[Graphical view]
PfamiPF00227. Proteasome. 1 hit.
PF10584. Proteasome_A_N. 1 hit.
[Graphical view]
SMARTiSM00948. Proteasome_A_N. 1 hit.
[Graphical view]
SUPFAMiSSF56235. SSF56235. 1 hit.
TIGRFAMsiTIGR03633. arc_protsome_A. 1 hit.
PROSITEiPS00388. PROTEASOME_ALPHA_1. 1 hit.
PS51475. PROTEASOME_ALPHA_2. 1 hit.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "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(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 23-30; 89-95 AND 150-163, BLOCKAGE OF N-TERMINUS, FUNCTION, CATALYTIC ACTIVITY, SUBSTRATE SPECIFICITY, BIOPHYSICOCHEMICAL PROPERTIES, ENZYME REGULATION, SALT REQUIREMENT, SUBUNIT.
  2. Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: ATCC 29605 / DSM 3757 / JCM 8879 / NBRC 14742 / NCIMB 2012 / VKM B-1768 / DS2.
  3. "Subunit topology of two 20S proteasomes from Haloferax volcanii."
    Kaczowka S.J., Maupin-Furlow J.A.
    J. Bacteriol. 185:165-174(2002) [PubMed] [Europe PMC] [Abstract]
    Cited for: SUBUNIT.
  4. "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(2003) [PubMed] [Europe PMC] [Abstract]
    Cited for: INDUCTION.
  5. "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(2005) [PubMed] [Europe PMC] [Abstract]
    Cited for: ACETYLATION AT MET-1, CLEAVAGE OF INITIATOR METHIONINE.
  6. "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(2007) [PubMed] [Europe PMC] [Abstract]
    Cited for: DISRUPTION PHENOTYPE.
  7. "The N-terminal penultimate residue of 20S proteasome alpha1 influences its N(alpha) acetylation and protein levels as well as growth rate and stress responses of Haloferax volcanii."
    Humbard M.A., Zhou G., Maupin-Furlow J.A.
    J. Bacteriol. 191:3794-3803(2008) [PubMed] [Europe PMC] [Abstract]
    Cited for: ACETYLATION, MUTAGENESIS OF GLN-2 AND 2-GLN--ARG-12.

Entry informationi

Entry nameiPSA1_HALVD
AccessioniPrimary (citable) accession number: Q9V2V6
Secondary accession number(s): D4GW11
Entry historyi
Integrated into UniProtKB/Swiss-Prot: December 7, 2000
Last sequence update: July 12, 2010
Last modified: March 31, 2015
This is version 92 of the entry and version 2 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Miscellaneousi

Miscellaneous

H.volcanii proteasome requires high concentrations of salt, similar to the extracellular environment and cytoplasm of this organism, for complex stability and optimal activity.

Keywords - Technical termi

Complete proteome, Direct protein sequencing, Reference proteome

Documents

  1. Peptidase families
    Classification of peptidase families and list of entries
  2. SIMILARITY comments
    Index of protein domains and families

External Data

Dasty 3

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into Uniref entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.