Q53080 · PSA1_RHOER
- ProteinProteasome subunit alpha 1
- GeneprcA1
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids259 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
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.
Activity 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.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
61.4 μM | Suc-Leu-Leu-Val-Tyr-AMC (with the beta2-alpha1 proteasome subtype) | |||||
66.4 μM | Suc-Leu-Leu-Val-Tyr-AMC (with the beta2-alpha2 proteasome subtype) | |||||
71.2 μM | Suc-Leu-Leu-Val-Tyr-AMC (with the beta1-alpha2 proteasome subtype) | |||||
84.3 μM | Suc-Leu-Leu-Val-Tyr-AMC (with the beta1-alpha1 proteasome subtype) |
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.
Pathway
Protein degradation; proteasomal Pup-dependent pathway.
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Cellular Component | proteasome core complex, alpha-subunit complex | |
Molecular Function | endopeptidase activity | |
Molecular Function | threonine-type endopeptidase activity | |
Biological Process | modification-dependent protein catabolic process | |
Biological Process | proteasomal protein catabolic process |
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameProteasome subunit alpha 1
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageBacteria > Actinomycetota > Actinomycetes > Mycobacteriales > Nocardiaceae > Rhodococcus > Rhodococcus erythropolis group
Accessions
- Primary accessionQ53080
Subcellular Location
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000397128 | 1-259 | Proteasome subunit alpha 1 | |||
Sequence: MTMPYYASAEQIMRDRSELARKGIARGRSVVVLTFRDGVLFVAENPSTALHKVSELYDRLGFAAVGKYNEFENLRRAGIVHADMRGYSYDRRDVTGRSLANAYAQTLGTIFTEQPKPYEVEICVAEVGRVGSPKAPQLYRITYDGSIVDEQHFVVMGGTTEPIATAMRESYRADLDLEAAVGIAVNALRQGGAGEGEKRNVDVASLEVAVLDQSRPRRAFRRIAGTALEQLVPAEPAAASESAPEPKPDTETKPADTQD |
Post-translational modification
The N-terminus is blocked.
Interaction
Subunit
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.
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | Intact | |
---|---|---|---|---|---|
BINARY | Q53080 | prcB1 Q53079 | 6 | EBI-1037564, EBI-1037574 |
Protein-protein interaction databases
Structure
Sequence
- Sequence statusComplete
- Length259
- Mass (Da)28,312
- Last updated1996-11-01 v1
- ChecksumC1A97CACA2D77050
Keywords
- Technical term