Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Poliovirus receptor

Gene

PVR

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Mediates NK cell adhesion and triggers NK cell effector functions. Binds two different NK cell receptors: CD96 and CD226. These interactions accumulates at the cell-cell contact site, leading to the formation of a mature immunological synapse between NK cell and target cell. This may trigger adhesion and secretion of lytic granules and IFN-gamma and activate cytoxicity of activated NK cells. May also promote NK cell-target cell modular exchange, and PVR transfer to the NK cell. This transfer is more important in some tumor cells expressing a lot of PVR, and may trigger fratricide NK cell activation, providing tumors with a mechanism of immunoevasion. Plays a role in mediating tumor cell invasion and migration.2 Publications
(Microbial infection) Acts as a receptor for poliovirus. May play a role in axonal transport of poliovirus, by targeting virion-PVR-containing endocytic vesicles to the microtubular network through interaction with DYNLT1. This interaction would drive the virus-containing vesicle to the axonal retrograde transport (PubMed:2538245). Acts as a receptor for pseudorabies virus (PubMed:9616127). Is prevented to reach cell surface upon infection by human cytomegalovirus /HHV-5, presumably to escape immune recognition of infected cell by NK cells (PubMed:15640804).3 Publications

Kineticsi

  1. KM=72 nM for VTN

    GO - Molecular functioni

    • cell adhesion molecule binding Source: BHF-UCL
    • protein homodimerization activity Source: GO_Central
    • receptor activity Source: ProtInc
    • receptor binding Source: GO_Central
    • virus receptor activity Source: UniProtKB-KW

    GO - Biological processi

    Complete GO annotation...

    Keywords - Molecular functioni

    Host cell receptor for virus entry, Receptor

    Keywords - Biological processi

    Cell adhesion, Host-virus interaction

    Enzyme and pathway databases

    BioCyciZFISH:ENSG00000073008-MONOMER.
    ReactomeiR-HSA-198933. Immunoregulatory interactions between a Lymphoid and a non-Lymphoid cell.
    R-HSA-420597. Nectin/Necl trans heterodimerization.

    Protein family/group databases

    MEROPSiI43.001.

    Names & Taxonomyi

    Protein namesi
    Recommended name:
    Poliovirus receptor
    Alternative name(s):
    Nectin-like protein 5
    Short name:
    NECL-5
    CD_antigen: CD155
    Gene namesi
    Name:PVR
    Synonyms:PVS
    OrganismiHomo sapiens (Human)
    Taxonomic identifieri9606 [NCBI]
    Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
    Proteomesi
    • UP000005640 Componenti: Chromosome 19

    Organism-specific databases

    HGNCiHGNC:9705. PVR.

    Subcellular locationi

    Topology

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Topological domaini21 – 343ExtracellularSequence analysisAdd BLAST323
    Transmembranei344 – 367HelicalSequence analysisAdd BLAST24
    Topological domaini368 – 417CytoplasmicSequence analysisAdd BLAST50

    GO - Cellular componenti

    • cell-cell adherens junction Source: GO_Central
    • cell surface Source: BHF-UCL
    • cytoplasm Source: ProtInc
    • extracellular exosome Source: UniProtKB
    • extracellular space Source: ProtInc
    • focal adhesion Source: UniProtKB
    • integral component of membrane Source: BHF-UCL
    • integral component of plasma membrane Source: GO_Central
    • plasma membrane Source: Reactome
    Complete GO annotation...

    Keywords - Cellular componenti

    Cell membrane, Membrane, Secreted

    Pathology & Biotechi

    Mutagenesis

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Mutagenesisi369 – 372KCSR → ACSA: Partial loss of DYNLT1 binding. 1 Publication4

    Organism-specific databases

    DisGeNETi5817.
    MIMi173850. gene+phenotype.
    OpenTargetsiENSG00000073008.
    PharmGKBiPA34050.

    Polymorphism and mutation databases

    BioMutaiPVR.
    DMDMi1346922.

    PTM / Processingi

    Molecule processing

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Signal peptidei1 – 20Sequence analysisAdd BLAST20
    ChainiPRO_000001513121 – 417Poliovirus receptorAdd BLAST397

    Amino acid modifications

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Disulfide bondi49 ↔ 123PROSITE-ProRule annotation1 Publication
    Glycosylationi105N-linked (GlcNAc...)1
    Glycosylationi120N-linked (GlcNAc...) (complex)1 Publication1
    Disulfide bondi166 ↔ 221PROSITE-ProRule annotation
    Glycosylationi188N-linked (GlcNAc...)Sequence analysis1
    Glycosylationi218N-linked (GlcNAc...)Sequence analysis1
    Glycosylationi237N-linked (GlcNAc...)Sequence analysis1
    Disulfide bondi266 ↔ 312PROSITE-ProRule annotation
    Glycosylationi278N-linked (GlcNAc...)1 Publication1
    Glycosylationi307N-linked (GlcNAc...)1 Publication1
    Glycosylationi313N-linked (GlcNAc...)Sequence analysis1
    Modified residuei398Phosphotyrosine2 Publications1

    Post-translational modificationi

    N-glycosylated. N-glycan at Asn-120: Hex5HexNAc4.3 Publications
    Phosphorylated by Src kinases on tyrosine residues in the ITIM motif upon ligation. Interaction with TIGIT is required for Phosphorylation.2 Publications

    Keywords - PTMi

    Disulfide bond, Glycoprotein, Phosphoprotein

    Proteomic databases

    EPDiP15151.
    MaxQBiP15151.
    PaxDbiP15151.
    PeptideAtlasiP15151.
    PRIDEiP15151.

    PTM databases

    iPTMnetiP15151.
    PhosphoSitePlusiP15151.
    SwissPalmiP15151.
    UniCarbKBiP15151.

    Expressioni

    Inductioni

    Transcriptionally regulated by SHH.1 Publication

    Gene expression databases

    BgeeiENSG00000073008.
    CleanExiHS_PVR.
    ExpressionAtlasiP15151. baseline and differential.
    GenevisibleiP15151. HS.

    Organism-specific databases

    HPAiHPA012568.

    Interactioni

    Subunit structurei

    Can form trans-heterodimers with NECTIN3. The extracellular domain interacts with VTN, CD226 and CD96. The cytoplasmic domain interacts with DYNLT1. Binds with high affinity to TIGIT.9 Publications
    (Microbial infection) Interacts with poliovirus capsid proteins.1 Publication
    (Microbial infection) Interacts with human cytomegalovirus /HHV-5 UL141 protein.1 Publication
    (Microbial infection) Interacts with pseudorabies virus gD protein.1 Publication

    Binary interactionsi

    WithEntry#Exp.IntActNotes
    KRTAP10-7P604093EBI-3919694,EBI-10172290
    KRTAP10-8P604103EBI-3919694,EBI-10171774
    KRTAP10-9P604113EBI-3919694,EBI-10172052
    NOTCH2NLQ7Z3S93EBI-3919694,EBI-945833
    SLC30A2Q9BRI33EBI-3919694,EBI-8644112

    GO - Molecular functioni

    • cell adhesion molecule binding Source: BHF-UCL
    • protein homodimerization activity Source: GO_Central
    • receptor binding Source: GO_Central

    Protein-protein interaction databases

    BioGridi111775. 51 interactors.
    DIPiDIP-43987N.
    IntActiP15151. 13 interactors.
    MINTiMINT-5224421.
    STRINGi9606.ENSP00000402060.

    Structurei

    Secondary structure

    1417
    Legend: HelixTurnBeta strandPDB Structure known for this area
    Show more details
    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Beta strandi30 – 32Combined sources3
    Beta strandi35 – 40Combined sources6
    Beta strandi45 – 47Combined sources3
    Beta strandi50 – 52Combined sources3
    Beta strandi60 – 68Combined sources9
    Beta strandi75 – 79Combined sources5
    Turni80 – 82Combined sources3
    Beta strandi83 – 86Combined sources4
    Beta strandi90 – 94Combined sources5
    Beta strandi108 – 110Combined sources3
    Helixi115 – 117Combined sources3
    Beta strandi119 – 128Combined sources10
    Beta strandi131 – 142Combined sources12

    3D structure databases

    Select the link destinations:
    PDBei
    RCSB PDBi
    PDBji
    Links Updated
    PDB entryMethodResolution (Å)ChainPositionsPDBsum
    1DGIelectron microscopy22.00R28-329[»]
    1NN8electron microscopy15.00R/S/T28-329[»]
    3EPCelectron microscopy8.00R30-242[»]
    3EPDelectron microscopy9.00R30-242[»]
    3EPFelectron microscopy9.00R30-242[»]
    3J8Felectron microscopy3.7071-417[»]
    3J9Felectron microscopy9.00728-143[»]
    8142-243[»]
    9242-333[»]
    3UDWX-ray2.90C/D28-145[»]
    3UROX-ray3.50R29-243[»]
    4FQPX-ray3.60A28-334[»]
    ProteinModelPortaliP15151.
    SMRiP15151.
    ModBaseiSearch...
    MobiDBiSearch...

    Miscellaneous databases

    EvolutionaryTraceiP15151.

    Family & Domainsi

    Domains and Repeats

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Domaini24 – 139Ig-like V-typeAdd BLAST116
    Domaini145 – 237Ig-like C2-type 1Add BLAST93
    Domaini244 – 328Ig-like C2-type 2Add BLAST85

    Region

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Regioni368 – 372DYNLT1 binding5

    Motif

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Motifi396 – 401ITIM motif6

    Domaini

    Contains 1 copy of a cytoplasmic motif that is referred to as the immunoreceptor tyrosine-based inhibitor motif (ITIM). The phosphorylated ITIM motif can bind the SH2 domain of several SH2-containing phosphatases.1 Publication

    Sequence similaritiesi

    Belongs to the nectin family.Curated

    Keywords - Domaini

    Immunoglobulin domain, Repeat, Signal, Transmembrane, Transmembrane helix

    Phylogenomic databases

    eggNOGiENOG410IY4J. Eukaryota.
    ENOG4111K6M. LUCA.
    GeneTreeiENSGT00770000120512.
    HOGENOMiHOG000237277.
    HOVERGENiHBG019169.
    InParanoidiP15151.
    KOiK06539.
    PhylomeDBiP15151.
    TreeFamiTF331051.

    Family and domain databases

    Gene3Di2.60.40.10. 3 hits.
    InterProiIPR013162. CD80_C2-set.
    IPR007110. Ig-like_dom.
    IPR013783. Ig-like_fold.
    IPR003599. Ig_sub.
    IPR013106. Ig_V-set.
    [Graphical view]
    PfamiPF08205. C2-set_2. 1 hit.
    PF07686. V-set. 1 hit.
    [Graphical view]
    SMARTiSM00409. IG. 2 hits.
    SM00406. IGv. 1 hit.
    [Graphical view]
    SUPFAMiSSF48726. SSF48726. 3 hits.
    PROSITEiPS50835. IG_LIKE. 3 hits.
    [Graphical view]

    Sequences (4)i

    Sequence statusi: Complete.

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

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

    Isoform Alpha (identifier: P15151-1) [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
    MARAMAAAWP LLLVALLVLS WPPPGTGDVV VQAPTQVPGF LGDSVTLPCY
    60 70 80 90 100
    LQVPNMEVTH VSQLTWARHG ESGSMAVFHQ TQGPSYSESK RLEFVAARLG
    110 120 130 140 150
    AELRNASLRM FGLRVEDEGN YTCLFVTFPQ GSRSVDIWLR VLAKPQNTAE
    160 170 180 190 200
    VQKVQLTGEP VPMARCVSTG GRPPAQITWH SDLGGMPNTS QVPGFLSGTV
    210 220 230 240 250
    TVTSLWILVP SSQVDGKNVT CKVEHESFEK PQLLTVNLTV YYPPEVSISG
    260 270 280 290 300
    YDNNWYLGQN EATLTCDARS NPEPTGYNWS TTMGPLPPFA VAQGAQLLIR
    310 320 330 340 350
    PVDKPINTTL ICNVTNALGA RQAELTVQVK EGPPSEHSGI SRNAIIFLVL
    360 370 380 390 400
    GILVFLILLG IGIYFYWSKC SREVLWHCHL CPSSTEHASA SANGHVSYSA
    410
    VSRENSSSQD PQTEGTR
    Length:417
    Mass (Da):45,303
    Last modified:February 1, 1996 - v2
    Checksum:iD15C012CE853169B
    GO
    Isoform Beta (identifier: P15151-2) [UniParc]FASTAAdd to basket

    The sequence of this isoform differs from the canonical sequence as follows:
         340-384: Missing.

    Note: Glycosylated on Asn-360.
    Show »
    Length:372
    Mass (Da):40,125
    Checksum:i7B56B38F949996BE
    GO
    Isoform Gamma (identifier: P15151-3) [UniParc]FASTAAdd to basket

    The sequence of this isoform differs from the canonical sequence as follows:
         331-331: E → G
         332-384: Missing.

    Note: Glycosylated on Asn-352.
    Show »
    Length:364
    Mass (Da):39,304
    Checksum:iF63D1B6CF19F2A6F
    GO
    Isoform Delta (identifier: P15151-4) [UniParc]FASTAAdd to basket

    The sequence of this isoform differs from the canonical sequence as follows:
         385-392: TEHASASA → EHHQSCRN
         393-417: Missing.

    Show »
    Length:392
    Mass (Da):42,864
    Checksum:i528DFC93B73C7FD8
    GO

    Natural variant

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Natural variantiVAR_00395267A → T.Corresponds to variant rs1058402dbSNPEnsembl.1
    Natural variantiVAR_049994295A → T.Corresponds to variant rs35365841dbSNPEnsembl.1
    Natural variantiVAR_011736340I → M.1 PublicationCorresponds to variant rs203710dbSNPEnsembl.1

    Alternative sequence

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Alternative sequenceiVSP_002618331E → G in isoform Gamma. Curated1
    Alternative sequenceiVSP_002619332 – 384Missing in isoform Gamma. CuratedAdd BLAST53
    Alternative sequenceiVSP_002617340 – 384Missing in isoform Beta. 1 PublicationAdd BLAST45
    Alternative sequenceiVSP_002620385 – 392TEHASASA → EHHQSCRN in isoform Delta. Curated8
    Alternative sequenceiVSP_002621393 – 417Missing in isoform Delta. CuratedAdd BLAST25

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    M24407 mRNA. Translation: AAA36461.1.
    M24406 mRNA. Translation: AAA36462.1.
    X64116
    , X64117, X64118, X64119, X64120, X64121, X64122, X64123 Genomic DNA. Translation: CAA45478.1.
    X64116
    , X64117, X64118, X64119, X64120, X64121, X64122, X64123 Genomic DNA. Translation: CAA45479.1.
    X64116
    , X64117, X64118, X64119, X64120, X64122, X64123 Genomic DNA. Translation: CAA45480.1.
    AK300349 mRNA. Translation: BAG62091.1.
    AC068948 Genomic DNA. Translation: AAF69803.1.
    BC015542 mRNA. Translation: AAH15542.1.
    CCDSiCCDS12640.1. [P15151-1]
    CCDS46105.1. [P15151-2]
    CCDS46106.1. [P15151-3]
    CCDS46107.1. [P15151-4]
    PIRiA43024. RWHUPD.
    S12048. RWHUPA.
    RefSeqiNP_001129240.1. NM_001135768.2. [P15151-2]
    NP_001129241.1. NM_001135769.2. [P15151-3]
    NP_001129242.2. NM_001135770.3.
    NP_006496.4. NM_006505.4.
    UniGeneiHs.171844.

    Genome annotation databases

    EnsembliENST00000344956; ENSP00000340870; ENSG00000073008. [P15151-3]
    ENST00000403059; ENSP00000385344; ENSG00000073008. [P15151-2]
    GeneIDi5817.
    KEGGihsa:5817.
    UCSCiuc032hzv.2. human. [P15151-1]

    Keywords - Coding sequence diversityi

    Alternative splicing, Polymorphism

    Cross-referencesi

    Web resourcesi

    Protein Spotlight

    The accidental crippler - Issue 75 of October 2006

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    M24407 mRNA. Translation: AAA36461.1.
    M24406 mRNA. Translation: AAA36462.1.
    X64116
    , X64117, X64118, X64119, X64120, X64121, X64122, X64123 Genomic DNA. Translation: CAA45478.1.
    X64116
    , X64117, X64118, X64119, X64120, X64121, X64122, X64123 Genomic DNA. Translation: CAA45479.1.
    X64116
    , X64117, X64118, X64119, X64120, X64122, X64123 Genomic DNA. Translation: CAA45480.1.
    AK300349 mRNA. Translation: BAG62091.1.
    AC068948 Genomic DNA. Translation: AAF69803.1.
    BC015542 mRNA. Translation: AAH15542.1.
    CCDSiCCDS12640.1. [P15151-1]
    CCDS46105.1. [P15151-2]
    CCDS46106.1. [P15151-3]
    CCDS46107.1. [P15151-4]
    PIRiA43024. RWHUPD.
    S12048. RWHUPA.
    RefSeqiNP_001129240.1. NM_001135768.2. [P15151-2]
    NP_001129241.1. NM_001135769.2. [P15151-3]
    NP_001129242.2. NM_001135770.3.
    NP_006496.4. NM_006505.4.
    UniGeneiHs.171844.

    3D structure databases

    Select the link destinations:
    PDBei
    RCSB PDBi
    PDBji
    Links Updated
    PDB entryMethodResolution (Å)ChainPositionsPDBsum
    1DGIelectron microscopy22.00R28-329[»]
    1NN8electron microscopy15.00R/S/T28-329[»]
    3EPCelectron microscopy8.00R30-242[»]
    3EPDelectron microscopy9.00R30-242[»]
    3EPFelectron microscopy9.00R30-242[»]
    3J8Felectron microscopy3.7071-417[»]
    3J9Felectron microscopy9.00728-143[»]
    8142-243[»]
    9242-333[»]
    3UDWX-ray2.90C/D28-145[»]
    3UROX-ray3.50R29-243[»]
    4FQPX-ray3.60A28-334[»]
    ProteinModelPortaliP15151.
    SMRiP15151.
    ModBaseiSearch...
    MobiDBiSearch...

    Protein-protein interaction databases

    BioGridi111775. 51 interactors.
    DIPiDIP-43987N.
    IntActiP15151. 13 interactors.
    MINTiMINT-5224421.
    STRINGi9606.ENSP00000402060.

    Protein family/group databases

    MEROPSiI43.001.

    PTM databases

    iPTMnetiP15151.
    PhosphoSitePlusiP15151.
    SwissPalmiP15151.
    UniCarbKBiP15151.

    Polymorphism and mutation databases

    BioMutaiPVR.
    DMDMi1346922.

    Proteomic databases

    EPDiP15151.
    MaxQBiP15151.
    PaxDbiP15151.
    PeptideAtlasiP15151.
    PRIDEiP15151.

    Protocols and materials databases

    DNASUi5817.
    Structural Biology KnowledgebaseSearch...

    Genome annotation databases

    EnsembliENST00000344956; ENSP00000340870; ENSG00000073008. [P15151-3]
    ENST00000403059; ENSP00000385344; ENSG00000073008. [P15151-2]
    GeneIDi5817.
    KEGGihsa:5817.
    UCSCiuc032hzv.2. human. [P15151-1]

    Organism-specific databases

    CTDi5817.
    DisGeNETi5817.
    GeneCardsiPVR.
    HGNCiHGNC:9705. PVR.
    HPAiHPA012568.
    MIMi173850. gene+phenotype.
    neXtProtiNX_P15151.
    OpenTargetsiENSG00000073008.
    PharmGKBiPA34050.
    GenAtlasiSearch...

    Phylogenomic databases

    eggNOGiENOG410IY4J. Eukaryota.
    ENOG4111K6M. LUCA.
    GeneTreeiENSGT00770000120512.
    HOGENOMiHOG000237277.
    HOVERGENiHBG019169.
    InParanoidiP15151.
    KOiK06539.
    PhylomeDBiP15151.
    TreeFamiTF331051.

    Enzyme and pathway databases

    BioCyciZFISH:ENSG00000073008-MONOMER.
    ReactomeiR-HSA-198933. Immunoregulatory interactions between a Lymphoid and a non-Lymphoid cell.
    R-HSA-420597. Nectin/Necl trans heterodimerization.

    Miscellaneous databases

    ChiTaRSiPVR. human.
    EvolutionaryTraceiP15151.
    GeneWikiiCD155.
    GenomeRNAii5817.
    PROiP15151.
    SOURCEiSearch...

    Gene expression databases

    BgeeiENSG00000073008.
    CleanExiHS_PVR.
    ExpressionAtlasiP15151. baseline and differential.
    GenevisibleiP15151. HS.

    Family and domain databases

    Gene3Di2.60.40.10. 3 hits.
    InterProiIPR013162. CD80_C2-set.
    IPR007110. Ig-like_dom.
    IPR013783. Ig-like_fold.
    IPR003599. Ig_sub.
    IPR013106. Ig_V-set.
    [Graphical view]
    PfamiPF08205. C2-set_2. 1 hit.
    PF07686. V-set. 1 hit.
    [Graphical view]
    SMARTiSM00409. IG. 2 hits.
    SM00406. IGv. 1 hit.
    [Graphical view]
    SUPFAMiSSF48726. SSF48726. 3 hits.
    PROSITEiPS50835. IG_LIKE. 3 hits.
    [Graphical view]
    ProtoNetiSearch...

    Entry informationi

    Entry nameiPVR_HUMAN
    AccessioniPrimary (citable) accession number: P15151
    Secondary accession number(s): B4DTS9
    , P15152, Q15267, Q15268, Q96BJ1
    Entry historyi
    Integrated into UniProtKB/Swiss-Prot: April 1, 1990
    Last sequence update: February 1, 1996
    Last modified: November 2, 2016
    This is version 184 of the entry and version 2 of the sequence. [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.

    Miscellaneousi

    Miscellaneous

    The V-type domain is necessary and sufficient for virus binding and uptake.

    Keywords - Technical termi

    3D-structure, Complete proteome, Reference proteome

    Documents

    1. Human cell differentiation molecules
      CD nomenclature of surface proteins of human leucocytes and list of entries
    2. Human chromosome 19
      Human chromosome 19: entries, gene names and cross-references to MIM
    3. Human entries with polymorphisms or disease mutations
      List of human entries with polymorphisms or disease mutations
    4. Human polymorphisms and disease mutations
      Index of human polymorphisms and disease mutations
    5. MIM cross-references
      Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
    6. PDB cross-references
      Index of Protein Data Bank (PDB) cross-references
    7. Protein Spotlight
      Protein Spotlight articles and cited UniProtKB/Swiss-Prot entries
    8. 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.