Q53084 (PSA2_RHOER) Reviewed, UniProtKB/Swiss-Prot
Last modified June 11, 2014. Version 60. History...
Names and origin
|Protein names||Recommended name:|
Proteasome subunit alpha 2
20S proteasome alpha subunit 2
Proteasome core protein PrcA 2
|Organism||Rhodococcus erythropolis (Arthrobacter picolinophilus)|
|Taxonomic identifier||1833 [NCBI]|
|Taxonomic lineage||Bacteria › Actinobacteria › Actinobacteridae › Actinomycetales › Corynebacterineae › Nocardiaceae › Rhodococcus|
|Sequence length||255 AA.|
|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 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
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
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
The N-terminus is blocked. HAMAP-Rule MF_00289
Belongs to the peptidase T1A family.
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)
|Technical term||Direct protein sequencing|
|Gene Ontology (GO)|
|Biological_process||proteasomal protein catabolic process|
Inferred from electronic annotation. Source: UniProtKB-SubCellproteasome core complex, alpha-subunit complex
|Molecular_function||endopeptidase activitythreonine-type endopeptidase activity|
Inferred from electronic annotation. Source: UniProtKB-KW
|Complete GO annotation...|
Sequence annotation (Features)
|||"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.
|||"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.
|U26422 Genomic DNA. Translation: AAC45737.1.|
3D structure databases
|SMR||Q53084. Positions 9-238. |
Protocols and materials databases
Enzyme and pathway databases
Family and domain databases
|Gene3D||188.8.131.52. 1 hit. |
|HAMAP||MF_00289_B. Proteasome_A_B. |
|InterPro||IPR029055. Ntn_hydrolases_N. |
|Pfam||PF00227. Proteasome. 1 hit. |
|SUPFAM||SSF56235. SSF56235. 1 hit. |
|TIGRFAMs||TIGR03691. 20S_bact_alpha. 1 hit. |
|PROSITE||PS51475. PROTEASOME_ALPHA_2. 1 hit. |
|Accession||Primary (citable) accession number: Q53084|
|Entry status||Reviewed (UniProtKB/Swiss-Prot)|
|Annotation program||Prokaryotic Protein Annotation Program|