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Protein

Toll-like receptor 9

Gene

Tlr9

Organism
Mus musculus (Mouse)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Key component of innate and adaptive immunity. TLRs (Toll-like receptors) control host immune response against pathogens through recognition of molecular patterns specific to microorganisms. TLR9 is a nucleotide-sensing TLR which is activated by unmethylated cytidine-phosphate-guanosine (CpG) dinucleotides. Acts via MYD88 and TRAF6, leading to NF-kappa-B activation, cytokine secretion and the inflammatory response. Plays a role in defense against systemic mouse cytomegalovirus infection. Controls lymphocyte response to Helicobacter infection.2 Publications

GO - Molecular functioni

GO - Biological processi

Complete GO annotation...

Keywords - Molecular functioni

Receptor

Keywords - Biological processi

Immunity, Inflammatory response, Innate immunity

Enzyme and pathway databases

ReactomeiR-MMU-109704. PI3K Cascade.
R-MMU-1679131. Trafficking and processing of endosomal TLR.
R-MMU-168138. Toll Like Receptor 9 (TLR9) Cascade.
R-MMU-975110. TRAF6 mediated IRF7 activation in TLR7/8 or 9 signaling.
R-MMU-975138. TRAF6 mediated induction of NFkB and MAP kinases upon TLR7/8 or 9 activation.
R-MMU-975155. MyD88 dependent cascade initiated on endosome.

Names & Taxonomyi

Protein namesi
Recommended name:
Toll-like receptor 9
Alternative name(s):
CD_antigen: CD289
Gene namesi
Name:Tlr9
OrganismiMus musculus (Mouse)
Taxonomic identifieri10090 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeMusMus
Proteomesi
  • UP000000589 Componenti: Chromosome 9

Organism-specific databases

MGIiMGI:1932389. Tlr9.

Subcellular locationi

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini26 – 818ExtracellularSequence analysisAdd BLAST793
Transmembranei819 – 839HelicalSequence analysisAdd BLAST21
Topological domaini840 – 1032CytoplasmicSequence analysisAdd BLAST193

GO - Cellular componenti

  • apical plasma membrane Source: MGI
  • basolateral plasma membrane Source: MGI
  • cytoplasm Source: MGI
  • early phagosome Source: UniProtKB
  • endoplasmic reticulum Source: UniProtKB
  • endoplasmic reticulum membrane Source: UniProtKB-SubCell
  • endosome Source: UniProtKB
  • integral component of membrane Source: UniProtKB-KW
  • lysosome Source: UniProtKB
  • plasma membrane Source: MGI
Complete GO annotation...

Keywords - Cellular componenti

Cytoplasmic vesicle, Endoplasmic reticulum, Endosome, Lysosome, Membrane

Pathology & Biotechi

Disruption phenotypei

Reduced proliferation of lymphocytes, reduced interferon-gamma production by splenocytes and reduced neutrophil numbers following Helicobacter infection.1 Publication

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi499L → P: Highly susceptible to mouse cytomegalovirus infection. Shows low level of cytokine induction and natural killer activation on viral infection. 1 Publication1

Chemistry databases

ChEMBLiCHEMBL6128.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 25Sequence analysisAdd BLAST25
ChainiPRO_000003473826 – 1032Toll-like receptor 9Add BLAST1007

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Glycosylationi64N-linked (GlcNAc...)Sequence analysis1
Glycosylationi129N-linked (GlcNAc...)Sequence analysis1
Glycosylationi147N-linked (GlcNAc...)Sequence analysis1
Glycosylationi200N-linked (GlcNAc...)Sequence analysis1
Glycosylationi210N-linked (GlcNAc...)Sequence analysis1
Glycosylationi242N-linked (GlcNAc...)Sequence analysis1
Glycosylationi300N-linked (GlcNAc...)Sequence analysis1
Glycosylationi309N-linked (GlcNAc...)Sequence analysis1
Glycosylationi332N-linked (GlcNAc...)Sequence analysis1
Glycosylationi340N-linked (GlcNAc...)Sequence analysis1
Glycosylationi495N-linked (GlcNAc...)Sequence analysis1
Glycosylationi514N-linked (GlcNAc...)Sequence analysis1
Glycosylationi568N-linked (GlcNAc...)Sequence analysis1
Glycosylationi670N-linked (GlcNAc...)Sequence analysis1
Glycosylationi695N-linked (GlcNAc...)Sequence analysis1
Glycosylationi700N-linked (GlcNAc...)Sequence analysis1
Glycosylationi732N-linked (GlcNAc...)Sequence analysis1
Glycosylationi752N-linked (GlcNAc...)Sequence analysis1

Keywords - PTMi

Glycoprotein

Proteomic databases

MaxQBiQ9EQU3.
PaxDbiQ9EQU3.
PeptideAtlasiQ9EQU3.
PRIDEiQ9EQU3.

PTM databases

iPTMnetiQ9EQU3.
PhosphoSitePlusiQ9EQU3.

Expressioni

Tissue specificityi

Expressed in the basolateral region of gastric epithelial cells with high levels detected in antrum and body mucosa (at protein level). Detected in spleen and stomach at higher levels in C57BL/6 mice than BALB/C.1 Publication

Inductioni

Following Helicobacter infection, down-regulated in C57BL/6 mice and up-regulated in BALB/C mice.1 Publication

Gene expression databases

BgeeiENSMUSG00000045322.
CleanExiMM_TLR9.
GenevisibleiQ9EQU3. MM.

Interactioni

Subunit structurei

Interacts with MYD88 via their respective TIR domains (By similarity). Interacts with BTK (By similarity). Interacts (via transmembrane domain) with UNC93B1. Interacts with CD300LH; the interaction may promote full activation of TLR9-triggered innate responses. Interacts with CNPY3 and HSP90B1; this interaction is required for proper folding in the endoplasmic reticulum. Interacts with SMPDL3B (PubMed:26095358).By similarity5 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
Atp2a2P115074EBI-9979528,EBI-916319From a different organism.

GO - Molecular functioni

Protein-protein interaction databases

IntActiQ9EQU3. 28 interactors.
STRINGi10090.ENSMUSP00000082207.

Structurei

Secondary structure

11032
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Turni31 – 34Combined sources4
Beta strandi35 – 38Combined sources4
Turni39 – 41Combined sources3
Beta strandi42 – 44Combined sources3
Beta strandi67 – 69Combined sources3
Turni80 – 83Combined sources4
Helixi84 – 86Combined sources3
Beta strandi90 – 93Combined sources4
Beta strandi100 – 102Combined sources3
Turni116 – 121Combined sources6
Beta strandi127 – 129Combined sources3
Beta strandi147 – 149Combined sources3
Helixi160 – 163Combined sources4
Beta strandi171 – 173Combined sources3
Beta strandi177 – 179Combined sources3
Turni192 – 197Combined sources6
Beta strandi203 – 205Combined sources3
Beta strandi223 – 226Combined sources4
Helixi237 – 239Combined sources3
Beta strandi247 – 250Combined sources4
Beta strandi254 – 256Combined sources3
Beta strandi269 – 272Combined sources4
Turni277 – 282Combined sources6
Beta strandi288 – 290Combined sources3
Helixi301 – 304Combined sources4
Beta strandi312 – 314Combined sources3
Beta strandi317 – 319Combined sources3
Helixi321 – 324Combined sources4
Helixi329 – 332Combined sources4
Beta strandi338 – 340Combined sources3
Beta strandi347 – 349Combined sources3
Helixi358 – 362Combined sources5
Beta strandi368 – 370Combined sources3
Beta strandi377 – 379Combined sources3
Turni381 – 384Combined sources4
Helixi385 – 387Combined sources3
Beta strandi395 – 397Combined sources3
Helixi408 – 412Combined sources5
Beta strandi413 – 416Combined sources4
Beta strandi419 – 421Combined sources3
Beta strandi473 – 475Combined sources3
Beta strandi477 – 479Combined sources3
Helixi490 – 493Combined sources4
Beta strandi501 – 503Combined sources3
Turni517 – 520Combined sources4
Beta strandi526 – 528Combined sources3
Turni539 – 544Combined sources6
Beta strandi550 – 552Combined sources3
Helixi570 – 574Combined sources5
Beta strandi580 – 582Combined sources3
Beta strandi590 – 592Combined sources3
Beta strandi597 – 600Combined sources4
Beta strandi603 – 605Combined sources3
Helixi611 – 615Combined sources5
Turni620 – 626Combined sources7
Beta strandi633 – 635Combined sources3
Helixi646 – 650Combined sources5
Beta strandi658 – 660Combined sources3
Helixi671 – 676Combined sources6
Beta strandi682 – 684Combined sources3
Beta strandi706 – 708Combined sources3
Turni719 – 724Combined sources6
Beta strandi730 – 732Combined sources3
Helixi743 – 745Combined sources3
Helixi747 – 751Combined sources5
Beta strandi754 – 757Combined sources4
Helixi771 – 777Combined sources7
Helixi779 – 781Combined sources3
Turni783 – 788Combined sources6
Beta strandi789 – 794Combined sources6
Turni795 – 797Combined sources3
Helixi807 – 809Combined sources3

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
3WPFX-ray1.96A26-818[»]
3WPGX-ray2.25A26-818[»]
3WPHX-ray2.33A26-818[»]
3WPIX-ray2.25A26-818[»]
4QDHX-ray2.40A/B480-753[»]
ProteinModelPortaliQ9EQU3.
SMRiQ9EQU3.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Repeati62 – 85LRR 1Add BLAST24
Repeati87 – 110LRR 2Add BLAST24
Repeati122 – 147LRR 3Add BLAST26
Repeati150 – 166LRR 4Add BLAST17
Repeati167 – 190LRR 5Add BLAST24
Repeati198 – 221LRR 6Add BLAST24
Repeati223 – 242LRR 7Add BLAST20
Repeati243 – 268LRR 8Add BLAST26
Repeati283 – 306LRR 9Add BLAST24
Repeati308 – 332LRR 10Add BLAST25
Repeati333 – 356LRR 11Add BLAST24
Repeati363 – 386LRR 12Add BLAST24
Repeati390 – 413LRR 13Add BLAST24
Repeati415 – 440LRR 14Add BLAST26
Repeati471 – 495LRR 15Add BLAST25
Repeati497 – 520LRR 16Add BLAST24
Repeati521 – 544LRR 17Add BLAST24
Repeati546 – 573LRR 18Add BLAST28
Repeati575 – 599LRR 19Add BLAST25
Repeati601 – 623LRR 20Add BLAST23
Repeati628 – 651LRR 21Add BLAST24
Repeati653 – 676LRR 22Add BLAST24
Repeati677 – 700LRR 23Add BLAST24
Repeati702 – 724LRR 24Add BLAST23
Repeati725 – 748LRR 25Add BLAST24
Repeati750 – 773LRR 26Add BLAST24
Domaini868 – 1016TIRPROSITE-ProRule annotationAdd BLAST149

Sequence similaritiesi

Belongs to the Toll-like receptor family.Curated
Contains 26 LRR (leucine-rich) repeats.Curated
Contains 1 TIR domain.PROSITE-ProRule annotation

Keywords - Domaini

Leucine-rich repeat, Repeat, Signal, Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiKOG4641. Eukaryota.
COG4886. LUCA.
GeneTreeiENSGT00760000119006.
HOGENOMiHOG000230468.
HOVERGENiHBG018601.
InParanoidiQ9EQU3.
KOiK10161.
OMAiRSNRIHH.
OrthoDBiEOG091G0BWK.
TreeFamiTF325595.

Family and domain databases

Gene3Di3.40.50.10140. 1 hit.
3.80.10.10. 5 hits.
InterProiIPR032675. L_dom-like.
IPR001611. Leu-rich_rpt.
IPR003591. Leu-rich_rpt_typical-subtyp.
IPR000157. TIR_dom.
IPR027181. TLR9.
[Graphical view]
PANTHERiPTHR24373:SF37. PTHR24373:SF37. 3 hits.
PfamiPF00560. LRR_1. 1 hit.
PF13855. LRR_8. 3 hits.
PF01582. TIR. 1 hit.
[Graphical view]
SMARTiSM00369. LRR_TYP. 15 hits.
SM00255. TIR. 1 hit.
[Graphical view]
SUPFAMiSSF52058. SSF52058. 1 hit.
SSF52200. SSF52200. 1 hit.
PROSITEiPS51450. LRR. 16 hits.
PS50104. TIR. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

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

Q9EQU3-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MVLRRRTLHP LSLLVQAAVL AETLALGTLP AFLPCELKPH GLVDCNWLFL
60 70 80 90 100
KSVPRFSAAA SCSNITRLSL ISNRIHHLHN SDFVHLSNLR QLNLKWNCPP
110 120 130 140 150
TGLSPLHFSC HMTIEPRTFL AMRTLEELNL SYNGITTVPR LPSSLVNLSL
160 170 180 190 200
SHTNILVLDA NSLAGLYSLR VLFMDGNCYY KNPCTGAVKV TPGALLGLSN
210 220 230 240 250
LTHLSLKYNN LTKVPRQLPP SLEYLLVSYN LIVKLGPEDL ANLTSLRVLD
260 270 280 290 300
VGGNCRRCDH APNPCIECGQ KSLHLHPETF HHLSHLEGLV LKDSSLHTLN
310 320 330 340 350
SSWFQGLVNL SVLDLSENFL YESITHTNAF QNLTRLRKLN LSFNYRKKVS
360 370 380 390 400
FARLHLASSF KNLVSLQELN MNGIFFRLLN KYTLRWLADL PKLHTLHLQM
410 420 430 440 450
NFINQAQLSI FGTFRALRFV DLSDNRISGP STLSEATPEE ADDAEQEELL
460 470 480 490 500
SADPHPAPLS TPASKNFMDR CKNFKFTMDL SRNNLVTIKP EMFVNLSRLQ
510 520 530 540 550
CLSLSHNSIA QAVNGSQFLP LTNLQVLDLS HNKLDLYHWK SFSELPQLQA
560 570 580 590 600
LDLSYNSQPF SMKGIGHNFS FVTHLSMLQS LSLAHNDIHT RVSSHLNSNS
610 620 630 640 650
VRFLDFSGNG MGRMWDEGGL YLHFFQGLSG LLKLDLSQNN LHILRPQNLD
660 670 680 690 700
NLPKSLKLLS LRDNYLSFFN WTSLSFLPNL EVLDLAGNQL KALTNGTLPN
710 720 730 740 750
GTLLQKLDVS SNSIVSVVPA FFALAVELKE VNLSHNILKT VDRSWFGPIV
760 770 780 790 800
MNLTVLDVRS NPLHCACGAA FVDLLLEVQT KVPGLANGVK CGSPGQLQGR
810 820 830 840 850
SIFAQDLRLC LDEVLSWDCF GLSLLAVAVG MVVPILHHLC GWDVWYCFHL
860 870 880 890 900
CLAWLPLLAR SRRSAQTLPY DAFVVFDKAQ SAVADWVYNE LRVRLEERRG
910 920 930 940 950
RRALRLCLED RDWLPGQTLF ENLWASIYGS RKTLFVLAHT DRVSGLLRTS
960 970 980 990 1000
FLLAQQRLLE DRKDVVVLVI LRPDAHRSRY VRLRQRLCRQ SVLFWPQQPN
1010 1020 1030
GQGGFWAQLS TALTRDNRHF YNQNFCRGPT AE
Length:1,032
Mass (Da):116,412
Last modified:December 14, 2011 - v3
Checksum:iC13A7888588CE297
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti325T → N in BAB19260 (PubMed:11130078).Curated1
Sequence conflicti325T → N in AAK29625 (PubMed:11470918).Curated1
Sequence conflicti325T → N in AAK28488 (PubMed:11867692).Curated1
Sequence conflicti325T → N in AAU04980 (PubMed:17474149).Curated1
Sequence conflicti378L → S in BAB19260 (PubMed:11130078).Curated1
Sequence conflicti378L → S in AAK29625 (PubMed:11470918).Curated1
Sequence conflicti378L → S in AAK28488 (PubMed:11867692).Curated1
Sequence conflicti378L → S in AAU04980 (PubMed:17474149).Curated1
Sequence conflicti554S → G in AAK28488 (PubMed:11867692).Curated1
Sequence conflicti562M → I in AAK28488 (PubMed:11867692).Curated1
Sequence conflicti573T → A in AAK29625 (PubMed:11470918).Curated1
Sequence conflicti573T → A in AAK28488 (PubMed:11867692).Curated1
Sequence conflicti573T → A in AAU04980 (PubMed:17474149).Curated1
Sequence conflicti579Q → H in AAK29625 (PubMed:11470918).Curated1
Sequence conflicti579Q → H in AAK28488 (PubMed:11867692).Curated1
Sequence conflicti579Q → H in AAU04980 (PubMed:17474149).Curated1
Sequence conflicti867T → A in AAK29625 (PubMed:11470918).Curated1
Sequence conflicti867T → A in AAK28488 (PubMed:11867692).Curated1
Sequence conflicti867T → A in AAU04980 (PubMed:17474149).Curated1
Sequence conflicti897E → G in AAK28488 (PubMed:11867692).Curated1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AB045181 mRNA. Translation: BAB19260.1.
AF348140 mRNA. Translation: AAK29625.1.
AF314224 mRNA. Translation: AAK28488.1.
AC164430 Genomic DNA. No translation available.
AY649790 Genomic DNA. Translation: AAU04980.1.
AY649791 Genomic DNA. Translation: AAU04981.1.
CCDSiCCDS40755.1.
RefSeqiNP_112455.2. NM_031178.2.
UniGeneiMm.44889.

Genome annotation databases

EnsembliENSMUST00000062241; ENSMUSP00000082207; ENSMUSG00000045322.
GeneIDi81897.
KEGGimmu:81897.
UCSCiuc009rjh.1. mouse.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AB045181 mRNA. Translation: BAB19260.1.
AF348140 mRNA. Translation: AAK29625.1.
AF314224 mRNA. Translation: AAK28488.1.
AC164430 Genomic DNA. No translation available.
AY649790 Genomic DNA. Translation: AAU04980.1.
AY649791 Genomic DNA. Translation: AAU04981.1.
CCDSiCCDS40755.1.
RefSeqiNP_112455.2. NM_031178.2.
UniGeneiMm.44889.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
3WPFX-ray1.96A26-818[»]
3WPGX-ray2.25A26-818[»]
3WPHX-ray2.33A26-818[»]
3WPIX-ray2.25A26-818[»]
4QDHX-ray2.40A/B480-753[»]
ProteinModelPortaliQ9EQU3.
SMRiQ9EQU3.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

IntActiQ9EQU3. 28 interactors.
STRINGi10090.ENSMUSP00000082207.

Chemistry databases

ChEMBLiCHEMBL6128.

PTM databases

iPTMnetiQ9EQU3.
PhosphoSitePlusiQ9EQU3.

Proteomic databases

MaxQBiQ9EQU3.
PaxDbiQ9EQU3.
PeptideAtlasiQ9EQU3.
PRIDEiQ9EQU3.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENSMUST00000062241; ENSMUSP00000082207; ENSMUSG00000045322.
GeneIDi81897.
KEGGimmu:81897.
UCSCiuc009rjh.1. mouse.

Organism-specific databases

CTDi54106.
MGIiMGI:1932389. Tlr9.

Phylogenomic databases

eggNOGiKOG4641. Eukaryota.
COG4886. LUCA.
GeneTreeiENSGT00760000119006.
HOGENOMiHOG000230468.
HOVERGENiHBG018601.
InParanoidiQ9EQU3.
KOiK10161.
OMAiRSNRIHH.
OrthoDBiEOG091G0BWK.
TreeFamiTF325595.

Enzyme and pathway databases

ReactomeiR-MMU-109704. PI3K Cascade.
R-MMU-1679131. Trafficking and processing of endosomal TLR.
R-MMU-168138. Toll Like Receptor 9 (TLR9) Cascade.
R-MMU-975110. TRAF6 mediated IRF7 activation in TLR7/8 or 9 signaling.
R-MMU-975138. TRAF6 mediated induction of NFkB and MAP kinases upon TLR7/8 or 9 activation.
R-MMU-975155. MyD88 dependent cascade initiated on endosome.

Miscellaneous databases

PROiQ9EQU3.
SOURCEiSearch...

Gene expression databases

BgeeiENSMUSG00000045322.
CleanExiMM_TLR9.
GenevisibleiQ9EQU3. MM.

Family and domain databases

Gene3Di3.40.50.10140. 1 hit.
3.80.10.10. 5 hits.
InterProiIPR032675. L_dom-like.
IPR001611. Leu-rich_rpt.
IPR003591. Leu-rich_rpt_typical-subtyp.
IPR000157. TIR_dom.
IPR027181. TLR9.
[Graphical view]
PANTHERiPTHR24373:SF37. PTHR24373:SF37. 3 hits.
PfamiPF00560. LRR_1. 1 hit.
PF13855. LRR_8. 3 hits.
PF01582. TIR. 1 hit.
[Graphical view]
SMARTiSM00369. LRR_TYP. 15 hits.
SM00255. TIR. 1 hit.
[Graphical view]
SUPFAMiSSF52058. SSF52058. 1 hit.
SSF52200. SSF52200. 1 hit.
PROSITEiPS51450. LRR. 16 hits.
PS50104. TIR. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiTLR9_MOUSE
AccessioniPrimary (citable) accession number: Q9EQU3
Secondary accession number(s): F8VPN5
, Q4L0K3, Q4L0K4, Q99MF2, Q99MQ8
Entry historyi
Integrated into UniProtKB/Swiss-Prot: January 31, 2002
Last sequence update: December 14, 2011
Last modified: November 2, 2016
This is version 146 of the entry and version 3 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. MGD cross-references
    Mouse Genome Database (MGD) cross-references in UniProtKB/Swiss-Prot
  2. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  3. 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.