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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-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-9033241 Peroxisomal protein import
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

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, 34 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


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

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: July 18, 2018
This is version 150 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


  1. Human chromosome 2
    Human chromosome 2: entries, gene names and cross-references to MIM
  2. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  3. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  4. Ribosomal proteins
    Ribosomal proteins families and list of entries
  5. SIMILARITY comments
    Index of protein domains and families

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