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Ubiquitin-40S ribosomal protein S27a



Homo sapiens (Human)
Reviewed-Annotation score: -Experimental evidence at protein leveli


Ubiquitin: Exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, DNA-damage responses as well as in signaling processes leading to activation of the transcription factor NF-kappa-B. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling.
40S Ribosomal protein S27a: Component of the 40S subunit of the ribosome.


Ubiquitin is encoded by 4 different genes. UBA52 and RPS27A genes code for a single copy of ubiquitin fused to the ribosomal proteins L40 and S27a, respectively. UBB and UBC genes code for a polyubiquitin precursor with exact head to tail repeats, the number of repeats differ between species and strains.
For a better understanding, features related to ubiquitin are only indicated for the first chain.


Feature keyPosition(s)DescriptionActionsGraphical viewLength
Binding sitei54Activating enzyme1
Sitei68Essential for function1
Binding sitei72Activating enzyme1


Feature keyPosition(s)DescriptionActionsGraphical viewLength
Zinc fingeri121 – 144C4-typeAdd BLAST24

GO - Molecular functioni

GO - Biological processi


Molecular functionRibonucleoprotein, Ribosomal protein
LigandMetal-binding, Zinc

Enzyme and pathway databases

ReactomeiR-HSA-110312. Translesion synthesis by REV1.
R-HSA-110314. Recognition of DNA damage by PCNA-containing replication complex.
R-HSA-110320. Translesion Synthesis by POLH.
R-HSA-1169091. Activation of NF-kappaB in B cells.
R-HSA-1169408. ISG15 antiviral mechanism.
R-HSA-1234176. Oxygen-dependent proline hydroxylation of Hypoxia-inducible Factor Alpha.
R-HSA-1236382. Constitutive Signaling by Ligand-Responsive EGFR Cancer Variants.
R-HSA-1236974. ER-Phagosome pathway.
R-HSA-1253288. Downregulation of ERBB4 signaling.
R-HSA-1295596. Spry regulation of FGF signaling.
R-HSA-1358803. Downregulation of ERBB2:ERBB3 signaling.
R-HSA-156827. L13a-mediated translational silencing of Ceruloplasmin expression.
R-HSA-156902. Peptide chain elongation.
R-HSA-162588. Budding and maturation of HIV virion.
R-HSA-168638. NOD1/2 Signaling Pathway.
R-HSA-168927. TICAM1, RIP1-mediated IKK complex recruitment.
R-HSA-168928. DDX58/IFIH1-mediated induction of interferon-alpha/beta.
R-HSA-174048. APC/C:Cdc20 mediated degradation of Cyclin B.
R-HSA-174084. Autodegradation of Cdh1 by Cdh1:APC/C.
R-HSA-174113. SCF-beta-TrCP mediated degradation of Emi1.
R-HSA-174154. APC/C:Cdc20 mediated degradation of Securin.
R-HSA-174178. APC/C:Cdh1 mediated degradation of Cdc20 and other APC/C:Cdh1 targeted proteins in late mitosis/early G1.
R-HSA-174184. Cdc20:Phospho-APC/C mediated degradation of Cyclin A.
R-HSA-174490. Membrane binding and targetting of GAG proteins.
R-HSA-175474. Assembly Of The HIV Virion.
R-HSA-179409. APC-Cdc20 mediated degradation of Nek2A.
R-HSA-1799339. SRP-dependent cotranslational protein targeting to membrane.
R-HSA-180534. Vpu mediated degradation of CD4.
R-HSA-180585. Vif-mediated degradation of APOBEC3G.
R-HSA-182971. EGFR downregulation.
R-HSA-187577. SCF(Skp2)-mediated degradation of p27/p21.
R-HSA-192823. Viral mRNA Translation.
R-HSA-195253. Degradation of beta-catenin by the destruction complex.
R-HSA-201681. TCF dependent signaling in response to WNT.
R-HSA-202424. Downstream TCR signaling.
R-HSA-205043. NRIF signals cell death from the nucleus.
R-HSA-209543. p75NTR recruits signalling complexes.
R-HSA-209560. NF-kB is activated and signals survival.
R-HSA-211733. Regulation of activated PAK-2p34 by proteasome mediated degradation.
R-HSA-2122947. NOTCH1 Intracellular Domain Regulates Transcription.
R-HSA-2122948. Activated NOTCH1 Transmits Signal to the Nucleus.
R-HSA-2173788. Downregulation of TGF-beta receptor signaling.
R-HSA-2173791. TGF-beta receptor signaling in EMT (epithelial to mesenchymal transition).
R-HSA-2173795. Downregulation of SMAD2/3:SMAD4 transcriptional activity.
R-HSA-2173796. SMAD2/SMAD3:SMAD4 heterotrimer regulates transcription.
R-HSA-2408557. Selenocysteine synthesis.
R-HSA-2467813. Separation of Sister Chromatids.
R-HSA-2559580. Oxidative Stress Induced Senescence.
R-HSA-2559582. Senescence-Associated Secretory Phenotype (SASP).
R-HSA-2559585. Oncogene Induced Senescence.
R-HSA-2565942. Regulation of PLK1 Activity at G2/M Transition.
R-HSA-2644606. Constitutive Signaling by NOTCH1 PEST Domain Mutants.
R-HSA-2672351. Stimuli-sensing channels.
R-HSA-2691232. Constitutive Signaling by NOTCH1 HD Domain Mutants.
R-HSA-2871837. FCERI mediated NF-kB activation.
R-HSA-2894862. Constitutive Signaling by NOTCH1 HD+PEST Domain Mutants.
R-HSA-2979096. NOTCH2 Activation and Transmission of Signal to the Nucleus.
R-HSA-3134975. Regulation of innate immune responses to cytosolic DNA.
R-HSA-3322077. Glycogen synthesis.
R-HSA-349425. Autodegradation of the E3 ubiquitin ligase COP1.
R-HSA-3769402. Deactivation of the beta-catenin transactivating complex.
R-HSA-3785653. Myoclonic epilepsy of Lafora.
R-HSA-382556. ABC-family proteins mediated transport.
R-HSA-400253. Circadian Clock.
R-HSA-445989. TAK1 activates NFkB by phosphorylation and activation of IKKs complex.
R-HSA-450302. activated TAK1 mediates p38 MAPK activation.
R-HSA-450321. JNK (c-Jun kinases) phosphorylation and activation mediated by activated human TAK1.
R-HSA-450408. AUF1 (hnRNP D0) binds and destabilizes mRNA.
R-HSA-4608870. Asymmetric localization of PCP proteins.
R-HSA-4641257. Degradation of AXIN.
R-HSA-4641258. Degradation of DVL.
R-HSA-4641263. Regulation of FZD by ubiquitination.
R-HSA-5205685. Pink/Parkin Mediated Mitophagy.
R-HSA-532668. N-glycan trimming in the ER and Calnexin/Calreticulin cycle.
R-HSA-5357905. Regulation of TNFR1 signaling.
R-HSA-5357956. TNFR1-induced NFkappaB signaling pathway.
R-HSA-5358346. Hedgehog ligand biogenesis.
R-HSA-5362768. Hh mutants that don't undergo autocatalytic processing are degraded by ERAD.
R-HSA-5607761. Dectin-1 mediated noncanonical NF-kB signaling.
R-HSA-5607764. CLEC7A (Dectin-1) signaling.
R-HSA-5610780. Degradation of GLI1 by the proteasome.
R-HSA-5610783. Degradation of GLI2 by the proteasome.
R-HSA-5610785. GLI3 is processed to GLI3R by the proteasome.
R-HSA-5632684. Hedgehog 'on' state.
R-HSA-5654726. Negative regulation of FGFR1 signaling.
R-HSA-5654727. Negative regulation of FGFR2 signaling.
R-HSA-5654732. Negative regulation of FGFR3 signaling.
R-HSA-5654733. Negative regulation of FGFR4 signaling.
R-HSA-5655862. Translesion synthesis by POLK.
R-HSA-5656121. Translesion synthesis by POLI.
R-HSA-5656169. Termination of translesion DNA synthesis.
R-HSA-5658442. Regulation of RAS by GAPs.
R-HSA-5668541. TNFR2 non-canonical NF-kB pathway.
R-HSA-5675221. Negative regulation of MAPK pathway.
R-HSA-5675482. Regulation of necroptotic cell death.
R-HSA-5676590. NIK-->noncanonical NF-kB signaling.
R-HSA-5678895. Defective CFTR causes cystic fibrosis.
R-HSA-5684264. MAP3K8 (TPL2)-dependent MAPK1/3 activation.
R-HSA-5685942. HDR through Homologous Recombination (HRR).
R-HSA-5687128. MAPK6/MAPK4 signaling.
R-HSA-5689603. UCH proteinases.
R-HSA-5689877. Josephin domain DUBs.
R-HSA-5689880. Ub-specific processing proteases.
R-HSA-5689896. Ovarian tumor domain proteases.
R-HSA-5689901. Metalloprotease DUBs.
R-HSA-5693565. Recruitment and ATM-mediated phosphorylation of repair and signaling proteins at DNA double strand breaks.
R-HSA-5693607. Processing of DNA double-strand break ends.
R-HSA-5696394. DNA Damage Recognition in GG-NER.
R-HSA-5696395. Formation of Incision Complex in GG-NER.
R-HSA-5696397. Gap-filling DNA repair synthesis and ligation in GG-NER.
R-HSA-5696400. Dual Incision in GG-NER.
R-HSA-6781823. Formation of TC-NER Pre-Incision Complex.
R-HSA-6781827. Transcription-Coupled Nucleotide Excision Repair (TC-NER).
R-HSA-6782135. Dual incision in TC-NER.
R-HSA-6782210. Gap-filling DNA repair synthesis and ligation in TC-NER.
R-HSA-6783310. Fanconi Anemia Pathway.
R-HSA-6791226. Major pathway of rRNA processing in the nucleolus and cytosol.
R-HSA-6804756. Regulation of TP53 Activity through Phosphorylation.
R-HSA-6804757. Regulation of TP53 Degradation.
R-HSA-6804760. Regulation of TP53 Activity through Methylation.
R-HSA-6807004. Negative regulation of MET activity.
R-HSA-68827. CDT1 association with the CDC6:ORC:origin complex.
R-HSA-68949. Orc1 removal from chromatin.
R-HSA-69017. CDK-mediated phosphorylation and removal of Cdc6.
R-HSA-69229. Ubiquitin-dependent degradation of Cyclin D1.
R-HSA-69231. Cyclin D associated events in G1.
R-HSA-69298. Association of licensing factors with the pre-replicative complex.
R-HSA-69481. G2/M Checkpoints.
R-HSA-69541. Stabilization of p53.
R-HSA-69601. Ubiquitin Mediated Degradation of Phosphorylated Cdc25A.
R-HSA-72649. Translation initiation complex formation.
R-HSA-72689. Formation of a pool of free 40S subunits.
R-HSA-72695. Formation of the ternary complex, and subsequently, the 43S complex.
R-HSA-72702. Ribosomal scanning and start codon recognition.
R-HSA-72706. GTP hydrolysis and joining of the 60S ribosomal subunit.
R-HSA-72764. Eukaryotic Translation Termination.
R-HSA-8849469. PTK6 Regulates RTKs and Their Effectors AKT1 and DOK1.
R-HSA-8852276. The role of GTSE1 in G2/M progression after G2 checkpoint.
R-HSA-8854050. FBXL7 down-regulates AURKA during mitotic entry and in early mitosis.
R-HSA-8856825. Cargo recognition for clathrin-mediated endocytosis.
R-HSA-8856828. Clathrin-mediated endocytosis.
R-HSA-8863795. Downregulation of ERBB2 signaling.
R-HSA-8866652. Synthesis of active ubiquitin: roles of E1 and E2 enzymes.
R-HSA-8866654. E3 ubiquitin ligases ubiquitinate target proteins.
R-HSA-8875360. InlB-mediated entry of Listeria monocytogenes into host cell.
R-HSA-8876493. InlA-mediated entry of Listeria monocytogenes into host cells.
R-HSA-8939236. RUNX1 regulates transcription of genes involved in differentiation of HSCs.
R-HSA-8939902. Regulation of RUNX2 expression and activity.
R-HSA-8941858. Regulation of RUNX3 expression and activity.
R-HSA-8948747. Regulation of PTEN localization.
R-HSA-8948751. Regulation of PTEN stability and activity.
R-HSA-8951664. Neddylation.
R-HSA-901032. ER Quality Control Compartment (ERQC).
R-HSA-9010553. Regulation of expression of SLITs and ROBOs.
R-HSA-9013507. NOTCH3 Activation and Transmission of Signal to the Nucleus.
R-HSA-9013973. TICAM1-dependent activation of IRF3/IRF7.
R-HSA-9014325. TICAM1,TRAF6-dependent induction of TAK1 complex.
R-HSA-9020702. Interleukin-1 signaling.
R-HSA-912631. Regulation of signaling by CBL.
R-HSA-917729. Endosomal Sorting Complex Required For Transport (ESCRT).
R-HSA-917937. Iron uptake and transport.
R-HSA-936440. Negative regulators of DDX58/IFIH1 signaling.
R-HSA-936964. Activation of IRF3/IRF7 mediated by TBK1/IKK epsilon.
R-HSA-937039. IRAK1 recruits IKK complex.
R-HSA-937041. IKK complex recruitment mediated by RIP1.
R-HSA-937042. IRAK2 mediated activation of TAK1 complex.
R-HSA-937072. TRAF6-mediated induction of TAK1 complex within TLR4 complex.
R-HSA-975110. TRAF6 mediated IRF7 activation in TLR7/8 or 9 signaling.
R-HSA-975144. IRAK1 recruits IKK complex upon TLR7/8 or 9 stimulation.
R-HSA-975163. IRAK2 mediated activation of TAK1 complex upon TLR7/8 or 9 stimulation.
R-HSA-975956. Nonsense Mediated Decay (NMD) independent of the Exon Junction Complex (EJC).
R-HSA-975957. Nonsense Mediated Decay (NMD) enhanced by the Exon Junction Complex (EJC).
R-HSA-977225. Amyloid fiber formation.
R-HSA-983168. Antigen processing: Ubiquitination & Proteasome degradation.

Names & Taxonomyi

Protein namesi
Recommended name:
Ubiquitin-40S ribosomal protein S27a
Alternative name(s):
Ubiquitin carboxyl extension protein 80
Cleaved into the following 2 chains:
Alternative name(s):
Small ribosomal subunit protein eS311 Publication
Gene namesi
Synonyms:UBA80, UBCEP1
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
  • UP000005640 Componenti: Chromosome 2

Organism-specific databases

HGNCiHGNC:10417. RPS27A.
MIMi191343. gene.

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Keywords - Cellular componenti

Cytoplasm, Nucleus

Pathology & Biotechi


Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi48K → R: No effect on HLTF-mediated polyubiquitination of PCNA. 1 Publication1
Mutagenesisi63K → R: Abolishes HLTF-mediated polyubiquitination of PCNA. 1 Publication1
Mutagenesisi65S → A: Prevents phosphorylation in case of mitophagy. 2 Publications1
Mutagenesisi65S → D: Phosphomimetic mutant that binds and activates PRKN. 1 Publication1

Organism-specific databases


Polymorphism and mutation databases


PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00003964771 – 76UbiquitinAdd BLAST76
ChainiPRO_000039647877 – 15640S ribosomal protein S27aAdd BLAST80

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Cross-linki6Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin)1 Publication
Cross-linki11Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin)2 Publications
Cross-linki27Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin)1 Publication
Cross-linki29Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin)1 Publication
Cross-linki48Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin)2 Publications
Cross-linki63Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin)2 Publications
Modified residuei65Phosphoserine; by PINK14 Publications1
Cross-linki76Glycyl lysine isopeptide (Gly-Lys) (interchain with K-? in acceptor proteins)
Modified residuei104N6-acetyllysineCombined sources1
Modified residuei113N6-acetyllysineCombined sources1
Modified residuei152N6-acetyllysineBy similarity1

Post-translational modificationi

Ubiquitin: Phosphorylated at Ser-65 by PINK1 during mitophagy. Phosphorylated ubiquitin specifically binds and activates parkin (PRKN), triggering mitophagy (PubMed:24660806, PubMed:24751536, PubMed:24784582, PubMed:25527291). Phosphorylation does not affect E1-mediated E2 charging of ubiquitin but affects discharging of E2 enzymes to form polyubiquitin chains. It also affects deubiquitination by deubiquitinase enzymes such as USP30 (PubMed:25527291).4 Publications

Keywords - PTMi

Acetylation, Isopeptide bond, Phosphoprotein, Ubl conjugation

Proteomic databases


PTM databases



Gene expression databases

ExpressionAtlasiP62979. baseline and differential.
GenevisibleiP62979. HS.

Organism-specific databases



Subunit structurei

Ribosomal protein S27a is part of the 40S ribosomal subunit.By similarity

Binary interactionsi

Show more details

Protein-protein interaction databases

BioGridi112147. 129 interactors.
IntActiP62979. 33 interactors.


Secondary structure

Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Beta strandi2 – 6Combined sources5
Beta strandi8 – 10Combined sources3
Beta strandi12 – 16Combined sources5
Helixi23 – 34Combined sources12
Helixi38 – 40Combined sources3
Beta strandi42 – 45Combined sources4
Helixi57 – 59Combined sources3
Beta strandi66 – 70Combined sources5

3D structure databases

Select the link destinations:
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
4UG0electron microscopy-Sf1-156[»]
4V6Xelectron microscopy5.00Af77-156[»]
5A2Qelectron microscopy3.90f78-149[»]
5AJ0electron microscopy3.50Bf1-156[»]
5FLXelectron microscopy3.90f1-156[»]
5LKSelectron microscopy3.60Sf1-156[»]
5T2Celectron microscopy3.60AH1-156[»]
6EK0electron microscopy2.90Sf1-156[»]

Miscellaneous databases


Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini1 – 76Ubiquitin-likePROSITE-ProRule annotationAdd BLAST76

Compositional bias

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Compositional biasi77 – 99Lys-rich (highly basic)Add BLAST23

Sequence similaritiesi

In the N-terminal section; belongs to the ubiquitin family.Curated
In the C-terminal section; belongs to the eukaryotic ribosomal protein eS31 family.Curated

Zinc finger

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Zinc fingeri121 – 144C4-typeAdd BLAST24

Keywords - Domaini


Phylogenomic databases

eggNOGiKOG0004. Eukaryota.
COG5272. LUCA.

Family and domain databases

Gene3Di2.20.25.660. 1 hit.
InterProiView protein in InterPro
IPR002906. Ribosomal_S27a.
IPR011332. Ribosomal_zn-bd.
IPR038582. S27a-like_sf.
IPR019956. Ubiquitin.
IPR029071. Ubiquitin-like_domsf.
IPR019954. Ubiquitin_CS.
IPR000626. Ubiquitin_dom.
PfamiView protein in Pfam
PF01599. Ribosomal_S27. 1 hit.
PF00240. ubiquitin. 1 hit.
SMARTiView protein in SMART
SM01402. Ribosomal_S27. 1 hit.
SM00213. UBQ. 1 hit.
SUPFAMiSSF54236. SSF54236. 1 hit.
SSF57829. SSF57829. 1 hit.
PROSITEiView protein in PROSITE
PS00299. UBIQUITIN_1. 1 hit.
PS50053. UBIQUITIN_2. 1 hit.


Sequence statusi: Complete.

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

P62979-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
60 70 80 90 100
110 120 130 140 150

Mass (Da):17,965
Last modified:August 10, 2010 - v2

Sequence databases

Select the link destinations:
Links Updated
X63237 mRNA. Translation: CAA44911.1.
S79522 mRNA. Translation: AAB21188.1.
AC012358 Genomic DNA. No translation available.
BC001392 mRNA. Translation: AAH01392.1.
BC066293 mRNA. Translation: AAH66293.1.
AB062071 Genomic DNA. Translation: BAB79490.1.
M10939 mRNA. Translation: AAA36788.1.
AB007163 Genomic DNA. Translation: BAA25826.1.
RefSeqiNP_001129064.1. NM_001135592.2.
NP_001170884.1. NM_001177413.1.
NP_002945.1. NM_002954.5.

Genome annotation databases

EnsembliENST00000272317; ENSP00000272317; ENSG00000143947.
ENST00000402285; ENSP00000383981; ENSG00000143947.
ENST00000404735; ENSP00000385659; ENSG00000143947.
UCSCiuc002ryk.4. human.

Similar proteinsi

Entry informationi

Entry nameiRS27A_HUMAN
AccessioniPrimary (citable) accession number: P62979
Secondary accession number(s): P02248
, P02249, P02250, P14798, P62988, Q29120, Q6LBL4, Q6LDU5, Q8WYN8, Q91887, Q91888, Q9BQ77, Q9BWD6, Q9BX98, Q9UEF2, Q9UEG1, Q9UEK8, Q9UPK7
Entry historyiIntegrated into UniProtKB/Swiss-Prot: August 31, 2004
Last sequence update: August 10, 2010
Last modified: March 28, 2018
This is version 146 of the entry and version 2 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.


Keywords - Technical termi

3D-structure, Complete proteome, Direct protein sequencing, Reference proteome