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

PAX-interacting protein 1

Gene

PAXIP1

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

Functioni

Involved in DNA damage response and in transcriptional regulation through histone methyltransferase (HMT) complexes. Plays a role in early development. In DNA damage response is required for cell survival after ionizing radiation. In vitro shown to be involved in the homologous recombination mechanism for the repair of double-strand breaks (DSBs). Its localization to DNA damage foci requires RNF8 and UBE2N. Recruits TP53BP1 to DNA damage foci and, at least in particular repair processes, effective DNA damage response appears to require the association with TP53BP1 phosphorylated by ATM at 'Ser-25'. Together with TP53BP1 regulates ATM association. Proposed to recruit PAGR1 to sites of DNA damage and the PAGR1:PAXIP1 complex is required for cell survival in response to DNA damage; the function is probably independent of MLL-containing histone methyltransferase (HMT) complexes. However, this function has been questioned (By similarity). Promotes ubiquitination of PCNA following UV irradiation and may regulate recruitment of polymerase eta and RAD51 to chromatin after DNA damage. Proposed to be involved in transcriptional regulation by linking MLL-containing histone methyltransferase (HMT) complexes to gene promoters by interacting with promoter-bound transcription factors such as PAX2. Associates with gene promoters that are known to be regulated by KMT2D/MLL2. During immunoglobulin class switching in activated B-cells is involved in trimethylation of histone H3 at 'Lys-4' and in transcription initiation of downstream switch regions at the immunoglobulin heavy-chain (Igh) locus; this function appears to involve the recruitment of MLL-containing HMT complexes. Conflictingly, its function in transcriptional regulation during immunoglobulin class switching is reported to be independent of the MLL2/MLL3 complex (By similarity).By similarity6 Publications

GO - Biological processi

Complete GO annotation...

Keywords - Biological processi

DNA damage, DNA recombination, DNA repair, Transcription, Transcription regulation

Enzyme and pathway databases

ReactomeiR-HSA-5617472. Activation of anterior HOX genes in hindbrain development during early embryogenesis.
R-HSA-5693571. Nonhomologous End-Joining (NHEJ).
SignaLinkiQ6ZW49.
SIGNORiQ6ZW49.

Names & Taxonomyi

Protein namesi
Recommended name:
PAX-interacting protein 1
Alternative name(s):
PAX transactivation activation domain-interacting protein
Gene namesi
Name:PAXIP1
Synonyms:PAXIP1L, PTIP
ORF Names:CAGF28
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 7

Organism-specific databases

HGNCiHGNC:8624. PAXIP1.

Subcellular locationi

GO - Cellular componenti

  • histone methyltransferase complex Source: UniProtKB
  • MLL3/4 complex Source: UniProtKB
  • nuclear matrix Source: UniProtKB-SubCell
  • nucleoplasm Source: Reactome
  • nucleus Source: UniProtKB
Complete GO annotation...

Keywords - Cellular componenti

Nucleus

Pathology & Biotechi

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi676W → A: Abolishes interaction with TP53BP1; prevents recruitment to DNA damage foci. 1 Publication1
Mutagenesisi910R → Q: Abolishes interaction with TP53BP1; impairs intact cellular response to DNA damage. 1 Publication1
Mutagenesisi929W → A: Abolishes interaction with TP53BP1; prevents recruitment to DNA damage foci. 1 Publication1

Organism-specific databases

DisGeNETi22976.
OpenTargetsiENSG00000157212.
PharmGKBiPA32964.

Polymorphism and mutation databases

BioMutaiPAXIP1.
DMDMi317373316.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00002962621 – 1069PAX-interacting protein 1Add BLAST1069

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei227PhosphoserineBy similarity1
Modified residuei235PhosphoserineCombined sources1

Keywords - PTMi

Phosphoprotein

Proteomic databases

EPDiQ6ZW49.
MaxQBiQ6ZW49.
PaxDbiQ6ZW49.
PeptideAtlasiQ6ZW49.
PRIDEiQ6ZW49.

PTM databases

iPTMnetiQ6ZW49.
PhosphoSitePlusiQ6ZW49.

Expressioni

Gene expression databases

BgeeiENSG00000157212.
CleanExiHS_PAXIP1.
ExpressionAtlasiQ6ZW49. baseline and differential.
GenevisibleiQ6ZW49. HS.

Organism-specific databases

HPAiHPA006694.
HPA016950.

Interactioni

Subunit structurei

Interacts with the C-terminal transactivation domain of PAX2 (By similarity). Forms a constitutive complex with PAGR1 independently of the MLL2/MLL3 complex. Interacts with TP53BP1 (phosphorylated at 'Ser-25'). Interacts with HLTF. Component of the KMT2 family MLL2/MLL3 complex (also named ASCOM complex), at least composed of the HMTs KMT2D and/or KMT2C, the common subunits ASH2L, RBBP5, WDR5 and DPY30, and the complex type-specific subunits PAXIP1/PTIP, PAGR1, NCOA6 and KDM6A; required for the association of PAGR1 with the MLL2/MLL3 complex.By similarity7 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
ASH2LQ9UBL311EBI-743225,EBI-540797
H2AFXP161047EBI-7521368,EBI-494830
MAPRE2Q155553EBI-10236271,EBI-739717
NXT1Q9UKK63EBI-10236271,EBI-301889
PAGR1Q9BTK68EBI-743225,EBI-2372223
POM121Q96HA13EBI-10236271,EBI-739990
RBBP5Q1529111EBI-743225,EBI-592823
TP53BP1Q128884EBI-743225,EBI-396540
WDR5P619648EBI-743225,EBI-540834

Protein-protein interaction databases

BioGridi116625. 261 interactors.
DIPiDIP-41786N.
IntActiQ6ZW49. 30 interactors.
MINTiMINT-276076.
STRINGi9606.ENSP00000384048.

Structurei

Secondary structure

11069
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Helixi863 – 865Combined sources3
Beta strandi868 – 871Combined sources4
Helixi876 – 888Combined sources13
Helixi897 – 899Combined sources3
Beta strandi901 – 904Combined sources4
Helixi912 – 917Combined sources6
Turni918 – 920Combined sources3
Beta strandi922 – 925Combined sources4
Helixi927 – 936Combined sources10
Helixi943 – 945Combined sources3
Helixi950 – 955Combined sources6
Helixi960 – 969Combined sources10
Turni972 – 975Combined sources4
Beta strandi976 – 980Combined sources5
Helixi988 – 997Combined sources10
Beta strandi1001 – 1005Combined sources5
Helixi1009 – 1017Combined sources9
Beta strandi1023 – 1028Combined sources6
Helixi1030 – 1036Combined sources7
Helixi1037 – 1041Combined sources5
Helixi1050 – 1058Combined sources9
Turni1063 – 1065Combined sources3

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
3SQDX-ray2.15A/B860-1069[»]
ProteinModelPortaliQ6ZW49.
SMRiQ6ZW49.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini8 – 93BRCT 1PROSITE-ProRule annotationAdd BLAST86
Domaini94 – 183BRCT 2PROSITE-ProRule annotationAdd BLAST90
Domaini601 – 694BRCT 3PROSITE-ProRule annotationAdd BLAST94
Domaini703 – 779BRCT 4PROSITE-ProRule annotationAdd BLAST77
Domaini866 – 947BRCT 5PROSITE-ProRule annotationAdd BLAST82
Domaini970 – 1059BRCT 6PROSITE-ProRule annotationAdd BLAST90

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni94 – 183Interaction with PAGR1By similarityAdd BLAST90
Regioni590 – 1069Interaction with TP53BP1Add BLAST480

Motif

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Motifi702 – 719Nuclear localization signalSequence analysisAdd BLAST18

Compositional bias

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Compositional biasi223 – 250Glu-richAdd BLAST28
Compositional biasi406 – 624Gln-richAdd BLAST219

Domaini

The BRCT 1 and 2 domains mediate the interaction with PAGR1A.By similarity
The BRCT 5 and 6 domains mediate the association with the MLL2/MLL3 complex (By similarity). The BRCT 5 and 6 domains function as a single module and are necessary and sufficient for in vitro phospho-specific binding (substrates phosphorylated by the kinases ataxia telangiectasia-mutated (ATM), ataxia telangiectasia and RAD3-related (ATR) in response to gamma irradiation). In contrast, in vivo two pairs of BRCT domains (3-6) bind to phosphorylated TP53BP1 much more efficiently.By similarity

Sequence similaritiesi

Contains 6 BRCT domains.PROSITE-ProRule annotation

Keywords - Domaini

Repeat

Phylogenomic databases

eggNOGiKOG2043. Eukaryota.
ENOG410XSGS. LUCA.
GeneTreeiENSGT00600000084454.
HOVERGENiHBG061191.
InParanoidiQ6ZW49.
KOiK14972.
OMAiMEHKQNS.
OrthoDBiEOG091G0YK0.
PhylomeDBiQ6ZW49.
TreeFamiTF329580.

Family and domain databases

CDDicd00027. BRCT. 4 hits.
Gene3Di3.40.50.10190. 5 hits.
InterProiIPR001357. BRCT_dom.
[Graphical view]
PfamiPF00533. BRCT. 1 hit.
PF12738. PTCB-BRCT. 2 hits.
PF16770. RTT107_BRCT_5. 1 hit.
[Graphical view]
SMARTiSM00292. BRCT. 5 hits.
[Graphical view]
SUPFAMiSSF52113. SSF52113. 5 hits.
PROSITEiPS50172. BRCT. 5 hits.
[Graphical view]

Sequences (3)i

Sequence statusi: Complete.

This entry describes 3 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform 1 (identifier: Q6ZW49-6) [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
MSDQAPKVPE EMFREVKYYA VGDIDPQVIQ LLKAGKAKEV SYNALASHII
60 70 80 90 100
SEDGDNPEVG EAREVFDLPV VKPSWVILSV QCGTLLPVNG FSPESCQIFF
110 120 130 140 150
GITACLSQVS SEDRSALWAL VTFYGGDCQL TLNKKCTHLI VPEPKGEKYE
160 170 180 190 200
CALKRASIKI VTPDWVLDCV SEKTKKDEAF YHPRLIIYEE EEEEEEEEEE
210 220 230 240 250
VENEEQDSQN EGSTDEKSSP ASSQEGSPSG DQQFSPKSNT EKSKGELMFD
260 270 280 290 300
DSSDSSPEKQ ERNLNWTPAE VPQLAAAKRR LPQGKEPGLI NLCANVPPVP
310 320 330 340 350
GNILPPEVRG NLMAAGQNLQ SSERSEMIAT WSPAVRTLRN ITNNADIQQM
360 370 380 390 400
NRPSNVAHIL QTLSAPTKNL EQQVNHSQQG HTNANAVLFS QVKVTPETHM
410 420 430 440 450
LQQQQQAQQQ QQQHPVLHLQ PQQIMQLQQQ QQQQISQQPY PQQPPHPFSQ
460 470 480 490 500
QQQQQQQAHP HQFSQQQLQF PQQQLHPPQQ LHRPQQQLQP FQQQHALQQQ
510 520 530 540 550
FHQLQQHQLQ QQQLAQLQQQ HSLLQQQQQQ QIQQQQLQRM HQQQQQQQMQ
560 570 580 590 600
SQTAPHLSQT SQALQHQVPP QQPPQQQQQQ QPPPSPQQHQ LFGHDPAVEI
610 620 630 640 650
PEEGFLLGCV FAIADYPEQM SDKQLLATWK RIIQAHGGTV DPTFTSRCTH
660 670 680 690 700
LLCESQVSSA YAQAIRERKR CVTAHWLNTV LKKKKMVPPH RALHFPVAFP
710 720 730 740 750
PGGKPCSQHI ISVTGFVDSD RDDLKLMAYL AGAKYTGYLC RSNTVLICKE
760 770 780 790 800
PTGLKYEKAK EWRIPCVNAQ WLGDILLGNF EALRQIQYSR YTAFSLQDPF
810 820 830 840 850
APTQHLVLNL LDAWRVPLKV SAELLMSIRL PPKLKQNEVA NVQPSSKRAR
860 870 880 890 900
IEDVPPPTKK LTPELTPFVL FTGFEPVQVQ QYIKKLYILG GEVAESAQKC
910 920 930 940 950
THLIASKVTR TVKFLTAISV VKHIVTPEWL EECFRCQKFI DEQNYILRDA
960 970 980 990 1000
EAEVLFSFSL EESLKRAHVS PLFKAKYFYI TPGICPSLST MKAIVECAGG
1010 1020 1030 1040 1050
KVLSKQPSFR KLMEHKQNSS LSEIILISCE NDLHLCREYF ARGIDVHNAE
1060
FVLTGVLTQT LDYESYKFN
Length:1,069
Mass (Da):121,341
Last modified:January 11, 2011 - v2
Checksum:i78CD535A150E1FC1
GO
Isoform 2 (identifier: Q6ZW49-1) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     1-108: MSDQAPKVPE...FFGITACLSQ → MVFLQNHVRF...QAEASVVMCW

Show »
Length:1,035
Mass (Da):117,690
Checksum:i3AB758354881AF7D
GO
Isoform 3 (identifier: Q6ZW49-2) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     1-247: Missing.

Note: No experimental confirmation available.
Show »
Length:822
Mass (Da):93,882
Checksum:i06D81BB07A314ED0
GO

Sequence cautioni

The sequence AAB91434 differs from that shown. Reason: Frameshift at positions 643 and 662.Curated
The sequence AAH33781 differs from that shown. Contaminating sequence.Curated
The sequence AAH33781 differs from that shown. Reason: Erroneous initiation. Translation N-terminally extended.Curated
The sequence AAP21865 differs from that shown. Reason: Erroneous gene model prediction.Curated
The sequence BAC85523 differs from that shown. Intron retention.Curated

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti121V → D in AK307417 (PubMed:14702039).Curated1
Sequence conflicti154K → R in CAE45762 (PubMed:17974005).Curated1
Sequence conflicti260Q → H in CAE45762 (PubMed:17974005).Curated1
Sequence conflicti406Missing in AK307417 (PubMed:14702039).Curated1
Sequence conflicti458 – 581Missing in AAB91434 (PubMed:9225980).CuratedAdd BLAST124
Sequence conflicti847K → Q in AAB91434 (PubMed:9225980).Curated1
Sequence conflicti912V → L in AAB91434 (PubMed:9225980).Curated1
Sequence conflicti916T → A in AAB91434 (PubMed:9225980).Curated1

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_0346271013M → V.1 PublicationCorresponds to variant rs3501dbSNPEnsembl.1

Alternative sequence

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Alternative sequenceiVSP_0403031 – 247Missing in isoform 3. 1 PublicationAdd BLAST247
Alternative sequenceiVSP_0403001 – 108MSDQA…ACLSQ → MVFLQNHVRFFLESLPAFLR VLIQAGALCWSLPELSQGEV GKGACPAEVGKHRDHLPSSD PVLMQAEASVVMCW in isoform 2. 1 PublicationAdd BLAST108

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AK123044 mRNA. Translation: BAC85523.1. Sequence problems.
AK123600 mRNA. Translation: BAC85657.1.
AK307417 mRNA. No translation available.
BX538201 mRNA. Translation: CAD98066.1.
BX640616 mRNA. Translation: CAE45762.1.
AC093726 Genomic DNA. Translation: AAP21865.1. Sequence problems.
U80735 mRNA. Translation: AAB91434.1. Frameshift.
BC008328 mRNA. Translation: AAH08328.1.
BC033781 mRNA. Translation: AAH33781.1. Sequence problems.
CCDSiCCDS47753.1. [Q6ZW49-6]
RefSeqiNP_031375.3. NM_007349.3. [Q6ZW49-6]
XP_005249596.1. XM_005249539.1. [Q6ZW49-1]
XP_016867370.1. XM_017011881.1. [Q6ZW49-1]
UniGeneiHs.443881.

Genome annotation databases

EnsembliENST00000397192; ENSP00000380376; ENSG00000157212. [Q6ZW49-6]
ENST00000404141; ENSP00000384048; ENSG00000157212. [Q6ZW49-6]
GeneIDi22976.
KEGGihsa:22976.
UCSCiuc033aqm.2. human. [Q6ZW49-6]

Keywords - Coding sequence diversityi

Alternative splicing, Polymorphism

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AK123044 mRNA. Translation: BAC85523.1. Sequence problems.
AK123600 mRNA. Translation: BAC85657.1.
AK307417 mRNA. No translation available.
BX538201 mRNA. Translation: CAD98066.1.
BX640616 mRNA. Translation: CAE45762.1.
AC093726 Genomic DNA. Translation: AAP21865.1. Sequence problems.
U80735 mRNA. Translation: AAB91434.1. Frameshift.
BC008328 mRNA. Translation: AAH08328.1.
BC033781 mRNA. Translation: AAH33781.1. Sequence problems.
CCDSiCCDS47753.1. [Q6ZW49-6]
RefSeqiNP_031375.3. NM_007349.3. [Q6ZW49-6]
XP_005249596.1. XM_005249539.1. [Q6ZW49-1]
XP_016867370.1. XM_017011881.1. [Q6ZW49-1]
UniGeneiHs.443881.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
3SQDX-ray2.15A/B860-1069[»]
ProteinModelPortaliQ6ZW49.
SMRiQ6ZW49.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi116625. 261 interactors.
DIPiDIP-41786N.
IntActiQ6ZW49. 30 interactors.
MINTiMINT-276076.
STRINGi9606.ENSP00000384048.

PTM databases

iPTMnetiQ6ZW49.
PhosphoSitePlusiQ6ZW49.

Polymorphism and mutation databases

BioMutaiPAXIP1.
DMDMi317373316.

Proteomic databases

EPDiQ6ZW49.
MaxQBiQ6ZW49.
PaxDbiQ6ZW49.
PeptideAtlasiQ6ZW49.
PRIDEiQ6ZW49.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000397192; ENSP00000380376; ENSG00000157212. [Q6ZW49-6]
ENST00000404141; ENSP00000384048; ENSG00000157212. [Q6ZW49-6]
GeneIDi22976.
KEGGihsa:22976.
UCSCiuc033aqm.2. human. [Q6ZW49-6]

Organism-specific databases

CTDi22976.
DisGeNETi22976.
GeneCardsiPAXIP1.
H-InvDBHIX0007243.
HGNCiHGNC:8624. PAXIP1.
HPAiHPA006694.
HPA016950.
MIMi608254. gene.
neXtProtiNX_Q6ZW49.
OpenTargetsiENSG00000157212.
PharmGKBiPA32964.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiKOG2043. Eukaryota.
ENOG410XSGS. LUCA.
GeneTreeiENSGT00600000084454.
HOVERGENiHBG061191.
InParanoidiQ6ZW49.
KOiK14972.
OMAiMEHKQNS.
OrthoDBiEOG091G0YK0.
PhylomeDBiQ6ZW49.
TreeFamiTF329580.

Enzyme and pathway databases

ReactomeiR-HSA-5617472. Activation of anterior HOX genes in hindbrain development during early embryogenesis.
R-HSA-5693571. Nonhomologous End-Joining (NHEJ).
SignaLinkiQ6ZW49.
SIGNORiQ6ZW49.

Miscellaneous databases

ChiTaRSiPAXIP1. human.
GeneWikiiPAXIP1.
GenomeRNAii22976.
PROiQ6ZW49.
SOURCEiSearch...

Gene expression databases

BgeeiENSG00000157212.
CleanExiHS_PAXIP1.
ExpressionAtlasiQ6ZW49. baseline and differential.
GenevisibleiQ6ZW49. HS.

Family and domain databases

CDDicd00027. BRCT. 4 hits.
Gene3Di3.40.50.10190. 5 hits.
InterProiIPR001357. BRCT_dom.
[Graphical view]
PfamiPF00533. BRCT. 1 hit.
PF12738. PTCB-BRCT. 2 hits.
PF16770. RTT107_BRCT_5. 1 hit.
[Graphical view]
SMARTiSM00292. BRCT. 5 hits.
[Graphical view]
SUPFAMiSSF52113. SSF52113. 5 hits.
PROSITEiPS50172. BRCT. 5 hits.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiPAXI1_HUMAN
AccessioniPrimary (citable) accession number: Q6ZW49
Secondary accession number(s): O15404
, Q6N099, Q6ZWH9, Q7Z315, Q86UN0, Q8N4P9, Q96HP2
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 24, 2007
Last sequence update: January 11, 2011
Last modified: November 30, 2016
This is version 110 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

Caution

The terminology of MLL proteins in mammalia is not consistent also concerning the terminology of MLL protein-containing complexes. The decribed MLL2/MLL3 complex is commonly described as MLL3/MLL4 complex in literature.Curated

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. Human chromosome 7
    Human chromosome 7: entries, gene names and cross-references to MIM
  2. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  3. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  4. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  5. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  6. 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.