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Protein

Small t antigen

Gene
N/A
Organism
Simian virus 40 (SV40)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Promotes efficient viral genome replication by accelerating both G1 and S phase progression of the cell cycle. Inhibits host PP2A by binding to the A subunit, thereby displacing lower affinity regulatory B subunit. Inactivation of PP2A in turn results in the transactivation of cyclin A and cyclin D1 promoters. Late during the infection cycle, ST may induce dephosphorylation of host eIF4E-binding protein EIF4EBP1 leading to the inhibition of cap-dependent translation. May establish and maintain high levels of viral genomes during persistent infection in cell culture.5 Publications

Regions

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Zinc fingeri103 – 116C4-type; atypicalAdd BLAST14
Zinc fingeri122 – 143H1C3-type; atypicalAdd BLAST22

GO - Molecular functioni

GO - Biological processi

Complete GO annotation...

Keywords - Molecular functioni

Activator

Keywords - Biological processi

Eukaryotic host gene expression shutoff by virus, Eukaryotic host translation shutoff by virus, Host gene expression shutoff by virus, Host-virus interaction, Transcription, Transcription regulation

Keywords - Ligandi

Metal-binding, Zinc

Names & Taxonomyi

Protein namesi
Recommended name:
Small t antigen
Short name:
ST
Short name:
ST-AG
OrganismiSimian virus 40 (SV40)
Taxonomic identifieri1891767 [NCBI]
Taxonomic lineageiVirusesdsDNA viruses, no RNA stagePolyomaviridae
Virus hostiMacaca (macaques) [TaxID: 9539]
Proteomesi
  • UP000007705 Componenti: Genome

Subcellular locationi

GO - Cellular componenti

Complete GO annotation...

Keywords - Cellular componenti

Host cytoplasm, Host nucleus

Pathology & Biotechi

Keywords - Diseasei

Oncogene

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00001150611 – 174Small t antigenAdd BLAST174

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei1N-acetylmethionine; by host1 Publication1

Keywords - PTMi

Acetylation, Phosphoprotein

Proteomic databases

PRIDEiP03081.

Expressioni

Keywords - Developmental stagei

Early protein

Interactioni

Subunit structurei

Interacts with host PPP2R1A; the interaction inhibits PP2A activity.2 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
PPP2R1AP301533EBI-1266256,EBI-302388From a different organism.
Ppp2r1aQ76MZ32EBI-1266256,EBI-400413From a different organism.

Protein-protein interaction databases

DIPiDIP-29393N.
IntActiP03081. 4 interactors.
MINTiMINT-1525558.

Structurei

Secondary structure

1174
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Turni2 – 4Combined sources3
Helixi7 – 15Combined sources9
Turni16 – 18Combined sources3
Helixi21 – 23Combined sources3
Helixi27 – 37Combined sources11
Helixi38 – 40Combined sources3
Turni50 – 53Combined sources4
Helixi54 – 69Combined sources16
Helixi73 – 76Combined sources4
Turni94 – 96Combined sources3
Helixi100 – 104Combined sources5
Beta strandi108 – 110Combined sources3
Helixi114 – 125Combined sources12
Turni126 – 128Combined sources3
Turni135 – 137Combined sources3
Helixi141 – 147Combined sources7
Helixi154 – 164Combined sources11

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
2PF4X-ray3.10E/F/G/H1-174[»]
2PKGX-ray3.30C/D87-174[»]
ProteinModelPortaliP03081.
SMRiP03081.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP03081.

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini12 – 75JPROSITE-ProRule annotationAdd BLAST64

Domaini

The common region of SV40 ST, 17kT and LT proteins comprises the J domain. This domain is essential for multiple viral activities, including virion assembly, viral DNA replication, transformation and transcriptional activation. This domain is also required for cyclin A-transactivating activity of ST.1 Publication

Sequence similaritiesi

Contains 1 J domain.PROSITE-ProRule annotation

Zinc finger

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Zinc fingeri103 – 116C4-type; atypicalAdd BLAST14
Zinc fingeri122 – 143H1C3-type; atypicalAdd BLAST22

Keywords - Domaini

Zinc-finger

Family and domain databases

CDDicd06257. DnaJ. 1 hit.
Gene3Di1.10.287.110. 1 hit.
InterProiIPR001623. DnaJ_domain.
IPR003354. Papo_T_antigen.
[Graphical view]
PfamiPF02380. Papo_T_antigen. 1 hit.
[Graphical view]
SMARTiSM00271. DnaJ. 1 hit.
[Graphical view]
SUPFAMiSSF46565. SSF46565. 1 hit.
PROSITEiPS50076. DNAJ_2. 1 hit.
[Graphical view]

Sequences (4)i

Sequence statusi: Complete.

This entry describes 4 isoformsi produced by alternative splicing. AlignAdd to basket

Note: Named isoforms=2.
Isoform Small t antigen (identifier: P03081-1) [UniParc]FASTAAdd to basket

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

« Hide

        10         20         30         40         50
MDKVLNREES LQLMDLLGLE RSAWGNIPLM RKAYLKKCKE FHPDKGGDEE
60 70 80 90 100
KMKKMNTLYK KMEDGVKYAH QPDFGGFWDA TEVFASSLNP GVDAMYCKQW
110 120 130 140 150
PECAKKMSAN CICLLCLLRM KHENRKLYRK DPLVWVDCYC FDCFRMWFGL
160 170
DLCEGTLLLW CDIIGQTTYR DLKL
Note: Produced by alternative splicing.
Length:174
Mass (Da):20,449
Last modified:July 21, 1986 - v1
Checksum:i91EC925ED2E29668
GO
Isoform Large T antigen (identifier: P03070-1) [UniParc]FASTAAdd to basket
The sequence of this isoform can be found in the external entry P03070.
Isoforms of the same protein are often annotated in two different entries if their sequences differ significantly.
Length:708
Mass (Da):81,582
GO
Isoform 17kT antigen (identifier: P03070-2) [UniParc]FASTAAdd to basket
The sequence of this isoform can be found in the external entry P03070.
Isoforms of the same protein are often annotated in two different entries if their sequences differ significantly.
Note: Produced by alternative splicing.
Length:135
Mass (Da):15,754
GO
Isoform SELP (identifier: P0C6L2-1) [UniParc]FASTAAdd to basket
The sequence of this isoform can be found in the external entry P0C6L2.
Isoforms of the same protein are often annotated in two different entries if their sequences differ significantly.
Note: Produced by alternative initiation.
Length:23
Mass (Da):2,705
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
J02400 Genomic DNA. Translation: AAB59925.1.
PIRiC03631. TVVPA4.
RefSeqiYP_003708383.1. NC_001669.1. [P03081-1]

Genome annotation databases

GeneIDi29031021.
KEGGivg:1489525.

Keywords - Coding sequence diversityi

Alternative initiation, Alternative splicing

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
J02400 Genomic DNA. Translation: AAB59925.1.
PIRiC03631. TVVPA4.
RefSeqiYP_003708383.1. NC_001669.1. [P03081-1]

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
2PF4X-ray3.10E/F/G/H1-174[»]
2PKGX-ray3.30C/D87-174[»]
ProteinModelPortaliP03081.
SMRiP03081.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

DIPiDIP-29393N.
IntActiP03081. 4 interactors.
MINTiMINT-1525558.

Proteomic databases

PRIDEiP03081.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

GeneIDi29031021.
KEGGivg:1489525.

Miscellaneous databases

EvolutionaryTraceiP03081.

Family and domain databases

CDDicd06257. DnaJ. 1 hit.
Gene3Di1.10.287.110. 1 hit.
InterProiIPR001623. DnaJ_domain.
IPR003354. Papo_T_antigen.
[Graphical view]
PfamiPF02380. Papo_T_antigen. 1 hit.
[Graphical view]
SMARTiSM00271. DnaJ. 1 hit.
[Graphical view]
SUPFAMiSSF46565. SSF46565. 1 hit.
PROSITEiPS50076. DNAJ_2. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiST_SV40
AccessioniPrimary (citable) accession number: P03081
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: July 21, 1986
Last modified: November 30, 2016
This is version 103 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  2. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.