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Q53084 (PSA2_RHOER) Reviewed, UniProtKB/Swiss-Prot

Last modified June 11, 2014. Version 60. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (3) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Proteasome subunit alpha 2

EC=3.4.25.1
Alternative name(s):
20S proteasome alpha subunit 2
Proteasome core protein PrcA 2
Gene names
Name:prcA2
OrganismRhodococcus erythropolis (Arthrobacter picolinophilus)
Taxonomic identifier1833 [NCBI]
Taxonomic lineageBacteriaActinobacteriaActinobacteridaeActinomycetalesCorynebacterineaeNocardiaceaeRhodococcus

Protein attributes

Sequence length255 AA.
Sequence statusComplete.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Component of the proteasome core, a large protease complex with broad specificity involved in protein degradation. The R.erythropolis proteasomes are able to cleave oligopeptides after Tyr, Phe and Leu, very poorly after Arg but not after Glu. Thus, displays chymotrypsin-like activity, low trypsin-like activity but no caspase-like activity. Ref.1 Ref.2

Catalytic activity

Cleavage of peptide bonds with very broad specificity. Ref.1 Ref.2

Enzyme regulation

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. HAMAP-Rule MF_00289

Pathway

Protein degradation; proteasomal Pup-dependent pathway. HAMAP-Rule MF_00289

Subunit structure

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. All four combinations of alpha- and beta-subunits (beta2-alpha1, beta2-alpha2, beta1-alpha2 and beta1-alpha1) yield fully assembled and proteolytically active proteasomes. 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 by the proteasome-associated ATPase, ARC. Ref.1 Ref.2

Subcellular location

Cytoplasm By similarity HAMAP-Rule MF_00289.

Post-translational modification

The N-terminus is blocked. HAMAP-Rule MF_00289

Sequence similarities

Belongs to the peptidase T1A family.

Biophysicochemical properties

Kinetic parameters:

The Vmax observed with the beta2-alpha1 proteasome subtype is 2.2-fold, 1.2-fold and 4-fold higher than that with the beta2-alpha2, beta1-alpha2 and beta1-alpha1 subtypes, respectively.

KM=61.4 µM for Suc-Leu-Leu-Val-Tyr-AMC (with the beta2-alpha1 proteasome subtype) Ref.2

KM=66.4 µM for Suc-Leu-Leu-Val-Tyr-AMC (with the beta2-alpha2 proteasome subtype)

KM=71.2 µM for Suc-Leu-Leu-Val-Tyr-AMC (with the beta1-alpha2 proteasome subtype)

KM=84.3 µM for Suc-Leu-Leu-Val-Tyr-AMC (with the beta1-alpha1 proteasome subtype)

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 255255Proteasome subunit alpha 2 HAMAP-Rule MF_00289
PRO_0000397129

Sequences

Sequence LengthMass (Da)Tools
Q53084 [UniParc].

Last modified November 1, 1996. Version 1.
Checksum: BCACDFEBDDB767B5

FASTA25527,859
        10         20         30         40         50         60 
MTMPYYASAE QIMRDRSELA RKGIARGRSV VVLTYRDGVL FVAENPSRAL HKVSELYDRL 

        70         80         90        100        110        120 
GFAAVGKYNE FENLRRAGIV HADMRGYSYD RRDVTGRSLA NAYAQTLGTI FTEQPKPYEV 

       130        140        150        160        170        180 
EICVAEIGRF GSSTPAQLYR ITYDGSIADE QEFVVMGGTT EPIVTAMRES YQRDLDLESA 

       190        200        210        220        230        240 
VRLAVGALQK GGPAPAGTTE AEPRTLDVSA LEVAVLDSNR PRRAFKRIAG SSLEEMLPTP 

       250 
AATEDAPPAN GDAPS 

« Hide

References

[1]"The first characterization of a eubacterial proteasome: the 20S complex of Rhodococcus."
Tamura T., Nagy I., Lupas A., Lottspeich F., Cejka Z., Schoofs G., Tanaka K., de Mot R., Baumeister W.
Curr. Biol. 5:766-774(1995) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PARTIAL PROTEIN SEQUENCE, BLOCKAGE OF N-TERMINUS, FUNCTION, CATALYTIC ACTIVITY, SUBSTRATE SPECIFICITY, SUBUNIT.
Strain: NI86/21.
[2]"Subunit topology of the Rhodococcus proteasome."
Zuhl F., Tamura T., Dolenc I., Cejka Z., Nagy I., De Mot R., Baumeister W.
FEBS Lett. 400:83-90(1997) [PubMed] [Europe PMC] [Abstract]
Cited for: SUBUNIT, FUNCTION, CATALYTIC ACTIVITY, SUBSTRATE SPECIFICITY, KINETIC PARAMETERS.
Strain: NI86/21.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
U26422 Genomic DNA. Translation: AAC45737.1.

3D structure databases

ProteinModelPortalQ53084.
SMRQ53084. Positions 9-238.
ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Enzyme and pathway databases

UniPathwayUPA00997.

Family and domain databases

Gene3D3.60.20.10. 1 hit.
HAMAPMF_00289_B. Proteasome_A_B.
InterProIPR029055. Ntn_hydrolases_N.
IPR022296. Proteasome_asu_bac.
IPR023332. Proteasome_suA-type.
IPR001353. Proteasome_sua/b.
[Graphical view]
PfamPF00227. Proteasome. 1 hit.
[Graphical view]
SUPFAMSSF56235. SSF56235. 1 hit.
TIGRFAMsTIGR03691. 20S_bact_alpha. 1 hit.
PROSITEPS51475. PROTEASOME_ALPHA_2. 1 hit.
[Graphical view]
ProtoNetSearch...

Entry information

Entry namePSA2_RHOER
AccessionPrimary (citable) accession number: Q53084
Entry history
Integrated into UniProtKB/Swiss-Prot: August 10, 2010
Last sequence update: November 1, 1996
Last modified: June 11, 2014
This is version 60 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

Peptidase families

Classification of peptidase families and list of entries

PATHWAY comments

Index of metabolic and biosynthesis pathways