ID   PSA1_HALVD              Reviewed;         252 AA.
AC   Q9V2V6; D4GW11;
DT   08-DEC-2000, integrated into UniProtKB/Swiss-Prot.
DT   13-JUL-2010, sequence version 2.
DT   27-MAR-2024, entry version 123.
DE   RecName: Full=Proteasome subunit alpha 1 {ECO:0000255|HAMAP-Rule:MF_00289};
DE   AltName: Full=20S proteasome alpha subunit 1 {ECO:0000255|HAMAP-Rule:MF_00289};
DE   AltName: Full=Proteasome core protein PsmA 1 {ECO:0000255|HAMAP-Rule:MF_00289};
DE   Contains:
DE     RecName: Full=Proteasome subunit alpha 1, N-terminally processed {ECO:0000255|HAMAP-Rule:MF_00289};
GN   Name=psmA1 {ECO:0000255|HAMAP-Rule:MF_00289}; Synonyms=psmA;
GN   OrderedLocusNames=HVO_1091;
OS   Haloferax volcanii (strain ATCC 29605 / DSM 3757 / JCM 8879 / NBRC 14742 /
OS   NCIMB 2012 / VKM B-1768 / DS2) (Halobacterium volcanii).
OC   Archaea; Euryarchaeota; Stenosarchaea group; Halobacteria; Haloferacales;
OC   Haloferacaceae; Haloferax.
OX   NCBI_TaxID=309800;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 23-30; 89-95 AND
RP   150-163, BLOCKAGE OF N-TERMINUS, FUNCTION, CATALYTIC ACTIVITY, SUBSTRATE
RP   SPECIFICITY, BIOPHYSICOCHEMICAL PROPERTIES, ACTIVITY REGULATION, SALT
RP   REQUIREMENT, AND SUBUNIT.
RX   PubMed=10482525; DOI=10.1128/jb.181.18.5814-5824.1999;
RA   Wilson H.L., Aldrich H.C., Maupin-Furlow J.;
RT   "Halophilic 20S proteasomes of the archaeon Haloferax volcanii:
RT   purification, characterization, and gene sequence analysis.";
RL   J. Bacteriol. 181:5814-5824(1999).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 29605 / DSM 3757 / JCM 8879 / NBRC 14742 / NCIMB 2012 /
RC   VKM B-1768 / DS2;
RX   PubMed=20333302; DOI=10.1371/journal.pone.0009605;
RA   Hartman A.L., Norais C., Badger J.H., Delmas S., Haldenby S., Madupu R.,
RA   Robinson J., Khouri H., Ren Q., Lowe T.M., Maupin-Furlow J.,
RA   Pohlschroder M., Daniels C., Pfeiffer F., Allers T., Eisen J.A.;
RT   "The complete genome sequence of Haloferax volcanii DS2, a model
RT   archaeon.";
RL   PLoS ONE 5:E9605-E9605(2010).
RN   [3]
RP   SUBUNIT.
RX   PubMed=12486053; DOI=10.1128/jb.185.1.165-174.2003;
RA   Kaczowka S.J., Maupin-Furlow J.A.;
RT   "Subunit topology of two 20S proteasomes from Haloferax volcanii.";
RL   J. Bacteriol. 185:165-174(2003).
RN   [4]
RP   INDUCTION.
RX   PubMed=15516591; DOI=10.1128/jb.186.22.7763-7772.2004;
RA   Reuter C.J., Kaczowka S.J., Maupin-Furlow J.A.;
RT   "Differential regulation of the PanA and PanB proteasome-activating
RT   nucleotidase and 20S proteasomal proteins of the haloarchaeon Haloferax
RT   volcanii.";
RL   J. Bacteriol. 186:7763-7772(2004).
RN   [5]
RP   ACETYLATION AT MET-1, AND CLEAVAGE OF INITIATOR METHIONINE.
RX   PubMed=16950923; DOI=10.1128/jb.00943-06;
RA   Humbard M.A., Stevens S.M. Jr., Maupin-Furlow J.A.;
RT   "Posttranslational modification of the 20S proteasomal proteins of the
RT   archaeon Haloferax volcanii.";
RL   J. Bacteriol. 188:7521-7530(2006).
RN   [6]
RP   DISRUPTION PHENOTYPE.
RX   PubMed=18931121; DOI=10.1128/jb.01180-08;
RA   Zhou G., Kowalczyk D., Humbard M.A., Rohatgi S., Maupin-Furlow J.A.;
RT   "Proteasomal components required for cell growth and stress responses in
RT   the haloarchaeon Haloferax volcanii.";
RL   J. Bacteriol. 190:8096-8105(2008).
RN   [7]
RP   ACETYLATION, AND MUTAGENESIS OF GLN-2 AND 2-GLN--ARG-12.
RX   PubMed=19376868; DOI=10.1128/jb.00090-09;
RA   Humbard M.A., Zhou G., Maupin-Furlow J.A.;
RT   "The N-terminal penultimate residue of 20S proteasome alpha1 influences its
RT   N(alpha) acetylation and protein levels as well as growth rate and stress
RT   responses of Haloferax volcanii.";
RL   J. Bacteriol. 191:3794-3803(2009).
CC   -!- FUNCTION: Component of the proteasome core, a large protease complex
CC       with broad specificity involved in protein degradation. The H.volcanii
CC       alpha1-beta proteasome is able to cleave oligopeptides after Phe, Tyr
CC       and Trp, poorly after Glu but not after Arg. Thus, displays
CC       chymotrypsin-like activity, low caspase-like activity but no trypsin-
CC       like activity. {ECO:0000255|HAMAP-Rule:MF_00289,
CC       ECO:0000269|PubMed:10482525}.
CC   -!- ACTIVITY REGULATION: The formation of the proteasomal ATPase PAN-20S
CC       proteasome complex, via the docking of the C-termini of PAN into the
CC       intersubunit pockets in the alpha-rings, triggers opening of the gate
CC       for substrate entry. Interconversion between the open-gate and close-
CC       gate conformations leads to a dynamic regulation of the 20S proteasome
CC       proteolysis activity (By similarity). In vitro, the chymotrypsin-like
CC       activity of the alpha1-beta proteasome is potently inhibited by
CC       carbobenzoxyl-leucinyl-leucinyl-leucinal-H (MG132) and significantly by
CC       N-acetyl-leucinyl-leucinyl-norleucinal-H (calpain inhibitor I).
CC       {ECO:0000255|HAMAP-Rule:MF_00289, ECO:0000269|PubMed:10482525}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       pH dependence:
CC         Optimum pH is 7.0-9.3 for the Suc-LLVY-Amc hydrolyzing activity (with
CC         the alpha1-beta proteasome subtype). {ECO:0000269|PubMed:10482525};
CC       Temperature dependence:
CC         Optimum temperature is 75 degrees Celsius for the Suc-LLVY-Amc
CC         hydrolyzing activity (with the alpha1-beta proteasome subtype).
CC         {ECO:0000269|PubMed:10482525};
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. H.volcanii produces at least 2 types
CC       of 20S proteasomes: an alpha1-beta proteasome and a proteasome
CC       containing all three subunits (alpha1, alpha2, and beta) that appears
CC       to be asymmetrical with homo-oligomeric alpha1 and alpha2 rings
CC       positioned on separate ends. The catalytic chamber with the active
CC       sites is on the inside of the barrel. Has probably a gated structure,
CC       the ends of the cylinder being occluded by the N-termini of the alpha-
CC       subunits. Is likely capped at one or both ends by the proteasome
CC       regulatory ATPase, PAN. {ECO:0000269|PubMed:10482525,
CC       ECO:0000269|PubMed:12486053}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_00289}.
CC   -!- INDUCTION: Up-regulated at the mRNA level during transition from
CC       exponential to stationary phase. However, at the protein level, PsmA 1
CC       is expressed at a high and relatively constant level throughout growth.
CC       {ECO:0000269|PubMed:15516591}.
CC   -!- PTM: Acetylated. The acetylated form at Met-1 was shown to be in 100-
CC       fold excess of the unacetylated form with the initiator methionine
CC       removed in whole cells and purified 20S proteasomes.
CC       {ECO:0000269|PubMed:16950923, ECO:0000269|PubMed:19376868}.
CC   -!- DISRUPTION PHENOTYPE: Strains lacking psmA1 gene alone display
CC       relatively normal growth rate and overall cell yield, but they are more
CC       sensitive to growth on organic versus inorganic nitrogen sources and
CC       hypo-osmotic stress, and they show limited growth in the presence of L-
CC       canavanine. Abolition of alpha1 subunit synthesis also has a severe
CC       impact on the ability of cells to withstand thermal stress. Moreover,
CC       depletion of psmA1 and psmA2 together renders the cells inviable.
CC       {ECO:0000269|PubMed:18931121}.
CC   -!- MISCELLANEOUS: H.volcanii proteasome requires high concentrations of
CC       salt, similar to the extracellular environment and cytoplasm of this
CC       organism, for complex stability and optimal activity.
CC   -!- SIMILARITY: Belongs to the peptidase T1A family. {ECO:0000255|HAMAP-
CC       Rule:MF_00289}.
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DR   EMBL; AF126260; AAD53404.1; -; Genomic_DNA.
DR   EMBL; CP001956; ADE04430.1; -; Genomic_DNA.
DR   PIR; T48678; T48678.
DR   RefSeq; WP_004043847.1; NZ_AOHU01000092.1.
DR   AlphaFoldDB; Q9V2V6; -.
DR   SMR; Q9V2V6; -.
DR   IntAct; Q9V2V6; 1.
DR   STRING; 309800.HVO_1091; -.
DR   iPTMnet; Q9V2V6; -.
DR   PaxDb; 309800-C498_13299; -.
DR   EnsemblBacteria; ADE04430; ADE04430; HVO_1091.
DR   GeneID; 8925549; -.
DR   KEGG; hvo:HVO_1091; -.
DR   eggNOG; arCOG00971; Archaea.
DR   HOGENOM; CLU_035750_4_1_2; -.
DR   OrthoDB; 9421at2157; -.
DR   Proteomes; UP000008243; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0019773; C:proteasome core complex, alpha-subunit complex; IDA:UniProtKB.
DR   GO; GO:0004175; F:endopeptidase activity; IDA:UniProtKB.
DR   GO; GO:0004298; F:threonine-type endopeptidase activity; IEA:InterPro.
DR   GO; GO:0010498; P:proteasomal protein catabolic process; IDA:UniProtKB.
DR   GO; GO:0006511; P:ubiquitin-dependent protein catabolic process; IEA:InterPro.
DR   CDD; cd03756; proteasome_alpha_archeal; 1.
DR   Gene3D; 3.60.20.10; Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1; 1.
DR   HAMAP; MF_00289_A; Proteasome_A_A; 1.
DR   InterPro; IPR029055; Ntn_hydrolases_N.
DR   InterPro; IPR023332; Proteasome_alpha-type.
DR   InterPro; IPR019982; Proteasome_asu_arc.
DR   InterPro; IPR000426; Proteasome_asu_N.
DR   InterPro; IPR001353; Proteasome_sua/b.
DR   NCBIfam; TIGR03633; arc_protsome_A; 1.
DR   PANTHER; PTHR11599:SF15; PROTEASOME SUBUNIT ALPHA TYPE-7-1-RELATED; 1.
DR   PANTHER; PTHR11599; PROTEASOME SUBUNIT ALPHA/BETA; 1.
DR   Pfam; PF00227; Proteasome; 1.
DR   Pfam; PF10584; Proteasome_A_N; 1.
DR   SMART; SM00948; Proteasome_A_N; 1.
DR   SUPFAM; SSF56235; N-terminal nucleophile aminohydrolases (Ntn hydrolases); 1.
DR   PROSITE; PS00388; PROTEASOME_ALPHA_1; 1.
DR   PROSITE; PS51475; PROTEASOME_ALPHA_2; 1.
PE   1: Evidence at protein level;
KW   Acetylation; Cytoplasm; Direct protein sequencing; Proteasome;
KW   Reference proteome.
FT   CHAIN           1..252
FT                   /note="Proteasome subunit alpha 1"
FT                   /id="PRO_0000124171"
FT   INIT_MET        1
FT                   /note="Removed; alternate"
FT                   /evidence="ECO:0000269|PubMed:16950923"
FT   CHAIN           2..252
FT                   /note="Proteasome subunit alpha 1, N-terminally processed"
FT                   /id="PRO_0000397604"
FT   MOD_RES         1
FT                   /note="N-acetylmethionine; alternate"
FT                   /evidence="ECO:0000269|PubMed:16950923"
FT   MUTAGEN         2..12
FT                   /note="Missing: Prevents acetylation of Met-1. Enhances
FT                   peptidase activity of the proteasome. Renders the cells
FT                   less tolerant of hypoosmotic stress than the wild-type."
FT                   /evidence="ECO:0000269|PubMed:19376868"
FT   MUTAGEN         2
FT                   /note="Q->A: Enhances cleavage of PsmA1 by methionine
FT                   aminopeptidase (MAP), resulting in acetylation of the
FT                   N-terminal alanine. Enhances peptidase activity of the
FT                   proteasome. Renders the cells less tolerant of hypoosmotic
FT                   stress than the wild-type."
FT                   /evidence="ECO:0000269|PubMed:19376868"
FT   MUTAGEN         2
FT                   /note="Q->D,P,T: Does not alter the prevalence of the
FT                   alpha1 subunit in N-acetylated form in proteasomes. Renders
FT                   the cells more tolerant of hypoosmotic and high-temperature
FT                   stress than the wild-type."
FT                   /evidence="ECO:0000269|PubMed:19376868"
FT   CONFLICT        96
FT                   /note="R -> H (in Ref. 1; AAD53404)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   252 AA;  27613 MW;  500A2DCCB0B71C71 CRC64;
     MQGQAQQQAY DRGITIFSPD GRLYQVEYAR EAVKRGTASI GVRTPEGVVL AADKRSRSPL
     MEPTSVEKIH KADDHIGIAS AGHVADARQL IDFARRQSQV NRLRYGEPIG IETLTKEVTD
     HIQQYTQVGG ARPFGVALLI GGVENGTPRL YETDPSGTPY EWKAVSIGAD RGDHQEHLEE
     NFRDDLTLDE GIELALEAIA STSDEGTAPD GVDVATVSAE TERFVELSND EIESYLEAND
     LLATEDDEQT EE
//