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Protein

Interference hedgehog

Gene

ihog

Organism
Drosophila melanogaster (Fruit fly)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Mediates response to the active Hedgehog (Hh) protein signal in embryos, functioning upstream or at the level of patched (ptc).1 Publication

Sites

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Binding sitei503 – 5031Heparin1 Publication
Binding sitei507 – 5071Heparin1 Publication
Binding sitei509 – 5091Heparin1 Publication
Binding sitei547 – 5471Heparin1 Publication

GO - Molecular functioni

  • hedgehog family protein binding Source: FlyBase
  • hedgehog receptor activity Source: FlyBase
  • heparin binding Source: UniProtKB
  • protein homodimerization activity Source: UniProtKB

GO - Biological processi

  • compound eye development Source: FlyBase
  • compound eye photoreceptor cell differentiation Source: FlyBase
  • cuticle pattern formation Source: FlyBase
  • negative regulation of Notch signaling pathway Source: FlyBase
  • positive regulation of smoothened signaling pathway Source: FlyBase
  • regulation of smoothened signaling pathway Source: FlyBase
  • smoothened signaling pathway Source: UniProtKB
  • wing disc pattern formation Source: FlyBase
Complete GO annotation...

Keywords - Ligandi

Heparin-binding

Enzyme and pathway databases

ReactomeiR-DME-375170. CDO in myogenesis.
R-DME-5632681. Ligand-receptor interactions.
SignaLinkiQ9VM64.

Names & Taxonomyi

Protein namesi
Recommended name:
Interference hedgehog1 Publication
Gene namesi
Name:ihog
ORF Names:CG9211
OrganismiDrosophila melanogaster (Fruit fly)
Taxonomic identifieri7227 [NCBI]
Taxonomic lineageiEukaryotaMetazoaEcdysozoaArthropodaHexapodaInsectaPterygotaNeopteraEndopterygotaDipteraBrachyceraMuscomorphaEphydroideaDrosophilidaeDrosophilaSophophora
Proteomesi
  • UP000000803 Componenti: Chromosome 2L

Organism-specific databases

FlyBaseiFBgn0031872. ihog.

Subcellular locationi

  • Membrane Sequence analysis; Single-pass type I membrane protein Sequence analysis1 Publication

Topology

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Topological domaini21 – 709689ExtracellularSequence analysisAdd
BLAST
Transmembranei710 – 73021HelicalSequence analysisAdd
BLAST
Topological domaini731 – 886156CytoplasmicSequence analysisAdd
BLAST

GO - Cellular componenti

  • cell surface Source: FlyBase
  • integral component of membrane Source: UniProtKB
Complete GO annotation...

Keywords - Cellular componenti

Membrane

Pathology & Biotechi

Disruption phenotypei

Patterning defects characteristic of Hh signaling loss in embryos and imaginal disks.1 Publication

Mutagenesis

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Mutagenesisi503 – 5031R → E: Loss of Heparin binding. 1 Publication
Mutagenesisi507 – 5071K → E: Loss of Heparin binding. 1 Publication
Mutagenesisi509 – 5091K → E: Loss of Heparin binding. 1 Publication
Mutagenesisi547 – 5471R → E: Loss of Heparin binding. 1 Publication

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Signal peptidei1 – 2020Sequence analysisAdd
BLAST
Chaini21 – 886866Interference hedgehogSequence analysisPRO_0000383615Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Disulfide bondi74 ↔ 132PROSITE-ProRule annotation
Glycosylationi108 – 1081N-linked (GlcNAc...)1 Publication
Disulfide bondi179 ↔ 226PROSITE-ProRule annotation
Glycosylationi215 – 2151N-linked (GlcNAc...)Sequence analysis
Disulfide bondi282 ↔ 330PROSITE-ProRule annotation
Disulfide bondi373 ↔ 420PROSITE-ProRule annotation
Glycosylationi472 – 4721N-linked (GlcNAc...)Sequence analysis
Glycosylationi563 – 5631N-linked (GlcNAc...)Sequence analysis
Glycosylationi699 – 6991N-linked (GlcNAc...)Sequence analysis

Keywords - PTMi

Disulfide bond, Glycoprotein, Proteoglycan

Proteomic databases

PaxDbiQ9VM64.
PRIDEiQ9VM64.

Expressioni

Developmental stagei

Expressed both maternally and zygotically.1 Publication

Gene expression databases

BgeeiQ9VM64.
GenevisibleiQ9VM64. DM.

Interactioni

Subunit structurei

Homodimer. Heterotetramer; 2 iHog chains bind 2 hh chains when facilitated by heparin, heparin is required to promote high-affinity interactions between hh and iHog.2 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
vnQ949182EBI-94134,EBI-869384

GO - Molecular functioni

  • hedgehog family protein binding Source: FlyBase
  • protein homodimerization activity Source: UniProtKB

Protein-protein interaction databases

DIPiDIP-35774N.
IntActiQ9VM64. 3 interactions.
STRINGi7227.FBpp0078993.

Structurei

Secondary structure

1
886
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Beta strandi472 – 4754Combined sources
Beta strandi477 – 4793Combined sources
Beta strandi481 – 4888Combined sources
Beta strandi495 – 50410Combined sources
Beta strandi512 – 5198Combined sources
Beta strandi522 – 5243Combined sources
Beta strandi526 – 53712Combined sources
Beta strandi542 – 55413Combined sources
Beta strandi559 – 5613Combined sources
Beta strandi568 – 5703Combined sources
Beta strandi573 – 5753Combined sources
Beta strandi591 – 5933Combined sources
Beta strandi595 – 6006Combined sources
Helixi607 – 6093Combined sources
Beta strandi612 – 6198Combined sources
Beta strandi627 – 6326Combined sources
Beta strandi638 – 6414Combined sources
Beta strandi649 – 6579Combined sources
Beta strandi669 – 6724Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
2IBBX-ray2.40A466-676[»]
2IBGX-ray2.20A/B/C/D466-677[»]
2IC2X-ray1.30A/B466-577[»]
ProteinModelPortaliQ9VM64.
SMRiQ9VM64. Positions 51-677.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiQ9VM64.

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini51 – 14898Ig-like C2-type 1Sequence analysisAdd
BLAST
Domaini138 – 238101Ig-like C2-type 2Sequence analysisAdd
BLAST
Domaini258 – 34689Ig-like C2-type 3Sequence analysisAdd
BLAST
Domaini352 – 43887Ig-like C2-type 4Sequence analysisAdd
BLAST
Domaini467 – 573107Fibronectin type-III 1PROSITE-ProRule annotationAdd
BLAST
Domaini581 – 67696Fibronectin type-III 2PROSITE-ProRule annotationAdd
BLAST

Compositional bias

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Compositional biasi781 – 7855Poly-GlnSequence analysis
Compositional biasi816 – 8194Poly-SerSequence analysis
Compositional biasi837 – 8459Poly-AsnSequence analysis

Domaini

The first Fibronectin type-III domain mediates a specific interaction with Hh protein, in vitro. The second Fibronectin type-III domain is additionally required for in vivo signaling activity.1 Publication

Sequence similaritiesi

Belongs to the immunoglobulin superfamily. IHOG family.Sequence analysis
Contains 2 fibronectin type-III domains.PROSITE-ProRule annotation
Contains 4 Ig-like C2-type (immunoglobulin-like) domains.Sequence analysis

Keywords - Domaini

Immunoglobulin domain, Repeat, Signal, Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiENOG410IHIH. Eukaryota.
ENOG410XSVT. LUCA.
GeneTreeiENSGT00840000129688.
InParanoidiQ9VM64.
OMAiNKPRMAE.
OrthoDBiEOG7GJ6D1.
PhylomeDBiQ9VM64.

Family and domain databases

Gene3Di2.60.40.10. 6 hits.
InterProiIPR003961. FN3_dom.
IPR007110. Ig-like_dom.
IPR013783. Ig-like_fold.
IPR003599. Ig_sub.
IPR003598. Ig_sub2.
IPR032988. iHog.
[Graphical view]
PANTHERiPTHR10489:SF732. PTHR10489:SF732. 2 hits.
PfamiPF00041. fn3. 2 hits.
PF13895. Ig_2. 1 hit.
[Graphical view]
SMARTiSM00060. FN3. 2 hits.
SM00409. IG. 4 hits.
SM00408. IGc2. 3 hits.
[Graphical view]
SUPFAMiSSF48726. SSF48726. 5 hits.
SSF49265. SSF49265. 1 hit.
PROSITEiPS50853. FN3. 2 hits.
PS50835. IG_LIKE. 4 hits.
[Graphical view]

Sequencei

Sequence statusi: Complete.

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

Q9VM64-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MTLLTSSLLL FSLLTSRLEA IPVLEKSPAH PAHSAHPAHP AHPAHPAHPS
60 70 80 90 100
PGVRILRAPE SLVAPLGDEV VLECETSLQP ERFEWSHRSS RSPGAGFKYL
110 120 130 140 150
KTGTAKANVS QEAAISRLRV LVRPDTLGEY RCVGWFGPLV VTSTIARLEL
160 170 180 190 200
ASTSLVDAQE SESPLQWRVS AGNSVLWSCG QQVQSNPSAS WSYYRNGVEI
210 220 230 240 250
KPEFIGTNGN LFLSNVSSES SGSYSCQATN PASGERIQLP GSLQLQVTPE
260 270 280 290 300
QRSESKSPHL LRGQPSSQEI TIREGSSLLL LCPGVGSPPP TVVWSSPDVV
310 320 330 340 350
GAVKNKRSKV FGHALEISNT RVNDAGTYIC FQDNGVRPAL EHYIKVHVEQ
360 370 380 390 400
PPQIVRPPWA DLTNEGDRLK LECKATGVPT PEIYWLLNGH SSIDDSEAEL
410 420 430 440 450
SNNFLILHSV LKRHAGYVQC FARNRLGEHS AGTLLQVNPK QIQEPRESGG
460 470 480 490 500
THRPKPNQGS RQKQMYPPTP PNVTRLSDES VMLRWMVPRN DGLPIVIFKV
510 520 530 540 550
QYRMVGKRKN WQTTNDNIPY GKPKWNSELG KSFTASVTDL KPQHTYRFRI
560 570 580 590 600
LAVYSNNDNK ESNTSAKFYL QPGAALDPMP VPELLEIEEY SETAVVLHWS
610 620 630 640 650
LASDADEHLI TGYYAYYRPS SSAGEYFKAT IEGAHARSFK IAPLETATMY
660 670 680 690 700
EFKLQSFSAA SASEFSALKQ GRTQRPKTST TEEPTLQMGD RDTTTPSHNE
710 720 730 740 750
TFNMSPMLTG TIGGGAVLIL LLISTCFCVC RRRNSRSRGN NPNKPRMAEL
760 770 780 790 800
RDDFVPLGNC SPTKQRQRTR HIHITLNPLA QQQQQALEEK NDTDQDAPYY
810 820 830 840 850
QRPSSYDYDP TLRRMSSSSL RRSQRTLERA GGSNGSNNGN NNNLNQSAEA
860 870 880
GSIENPGKPG RVLMKRPRLS SRSENLSSGS LNSVGV
Length:886
Mass (Da):97,846
Last modified:May 1, 2000 - v1
Checksum:i8DA038FA9107E227
GO

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti47 – 493Missing in ABA86412 (PubMed:16120803).Curated
Sequence conflicti242 – 2421S → L in ABA86412 (PubMed:16120803).Curated
Sequence conflicti250 – 2501E → D in ABA86412 (PubMed:16120803).Curated
Sequence conflicti254 – 2541E → Q in ABA86412 (PubMed:16120803).Curated
Sequence conflicti323 – 3231N → H in ABA86412 (PubMed:16120803).Curated
Sequence conflicti374 – 3741K → E in ABA86412 (PubMed:16120803).Curated

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AE014134 Genomic DNA. Translation: AAF52461.1.
AY119465 mRNA. Translation: AAM50119.1.
DQ138806 Genomic DNA. Translation: ABA86412.1.
BT071816 mRNA. Translation: ACN58579.1.
RefSeqiNP_609085.1. NM_135241.2.
UniGeneiDm.11441.

Genome annotation databases

EnsemblMetazoaiFBtr0079365; FBpp0078993; FBgn0031872.
GeneIDi33972.
KEGGidme:Dmel_CG9211.
UCSCiCG9211-RA. d. melanogaster.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AE014134 Genomic DNA. Translation: AAF52461.1.
AY119465 mRNA. Translation: AAM50119.1.
DQ138806 Genomic DNA. Translation: ABA86412.1.
BT071816 mRNA. Translation: ACN58579.1.
RefSeqiNP_609085.1. NM_135241.2.
UniGeneiDm.11441.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
2IBBX-ray2.40A466-676[»]
2IBGX-ray2.20A/B/C/D466-677[»]
2IC2X-ray1.30A/B466-577[»]
ProteinModelPortaliQ9VM64.
SMRiQ9VM64. Positions 51-677.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

DIPiDIP-35774N.
IntActiQ9VM64. 3 interactions.
STRINGi7227.FBpp0078993.

Proteomic databases

PaxDbiQ9VM64.
PRIDEiQ9VM64.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblMetazoaiFBtr0079365; FBpp0078993; FBgn0031872.
GeneIDi33972.
KEGGidme:Dmel_CG9211.
UCSCiCG9211-RA. d. melanogaster.

Organism-specific databases

CTDi33972.
FlyBaseiFBgn0031872. ihog.

Phylogenomic databases

eggNOGiENOG410IHIH. Eukaryota.
ENOG410XSVT. LUCA.
GeneTreeiENSGT00840000129688.
InParanoidiQ9VM64.
OMAiNKPRMAE.
OrthoDBiEOG7GJ6D1.
PhylomeDBiQ9VM64.

Enzyme and pathway databases

ReactomeiR-DME-375170. CDO in myogenesis.
R-DME-5632681. Ligand-receptor interactions.
SignaLinkiQ9VM64.

Miscellaneous databases

EvolutionaryTraceiQ9VM64.
GenomeRNAii33972.
PROiQ9VM64.

Gene expression databases

BgeeiQ9VM64.
GenevisibleiQ9VM64. DM.

Family and domain databases

Gene3Di2.60.40.10. 6 hits.
InterProiIPR003961. FN3_dom.
IPR007110. Ig-like_dom.
IPR013783. Ig-like_fold.
IPR003599. Ig_sub.
IPR003598. Ig_sub2.
IPR032988. iHog.
[Graphical view]
PANTHERiPTHR10489:SF732. PTHR10489:SF732. 2 hits.
PfamiPF00041. fn3. 2 hits.
PF13895. Ig_2. 1 hit.
[Graphical view]
SMARTiSM00060. FN3. 2 hits.
SM00409. IG. 4 hits.
SM00408. IGc2. 3 hits.
[Graphical view]
SUPFAMiSSF48726. SSF48726. 5 hits.
SSF49265. SSF49265. 1 hit.
PROSITEiPS50853. FN3. 2 hits.
PS50835. IG_LIKE. 4 hits.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "The genome sequence of Drosophila melanogaster."
    Adams M.D., Celniker S.E., Holt R.A., Evans C.A., Gocayne J.D., Amanatides P.G., Scherer S.E., Li P.W., Hoskins R.A., Galle R.F., George R.A., Lewis S.E., Richards S., Ashburner M., Henderson S.N., Sutton G.G., Wortman J.R., Yandell M.D.
    , Zhang Q., Chen L.X., Brandon R.C., Rogers Y.-H.C., Blazej R.G., Champe M., Pfeiffer B.D., Wan K.H., Doyle C., Baxter E.G., Helt G., Nelson C.R., Miklos G.L.G., Abril J.F., Agbayani A., An H.-J., Andrews-Pfannkoch C., Baldwin D., Ballew R.M., Basu A., Baxendale J., Bayraktaroglu L., Beasley E.M., Beeson K.Y., Benos P.V., Berman B.P., Bhandari D., Bolshakov S., Borkova D., Botchan M.R., Bouck J., Brokstein P., Brottier P., Burtis K.C., Busam D.A., Butler H., Cadieu E., Center A., Chandra I., Cherry J.M., Cawley S., Dahlke C., Davenport L.B., Davies P., de Pablos B., Delcher A., Deng Z., Mays A.D., Dew I., Dietz S.M., Dodson K., Doup L.E., Downes M., Dugan-Rocha S., Dunkov B.C., Dunn P., Durbin K.J., Evangelista C.C., Ferraz C., Ferriera S., Fleischmann W., Fosler C., Gabrielian A.E., Garg N.S., Gelbart W.M., Glasser K., Glodek A., Gong F., Gorrell J.H., Gu Z., Guan P., Harris M., Harris N.L., Harvey D.A., Heiman T.J., Hernandez J.R., Houck J., Hostin D., Houston K.A., Howland T.J., Wei M.-H., Ibegwam C., Jalali M., Kalush F., Karpen G.H., Ke Z., Kennison J.A., Ketchum K.A., Kimmel B.E., Kodira C.D., Kraft C.L., Kravitz S., Kulp D., Lai Z., Lasko P., Lei Y., Levitsky A.A., Li J.H., Li Z., Liang Y., Lin X., Liu X., Mattei B., McIntosh T.C., McLeod M.P., McPherson D., Merkulov G., Milshina N.V., Mobarry C., Morris J., Moshrefi A., Mount S.M., Moy M., Murphy B., Murphy L., Muzny D.M., Nelson D.L., Nelson D.R., Nelson K.A., Nixon K., Nusskern D.R., Pacleb J.M., Palazzolo M., Pittman G.S., Pan S., Pollard J., Puri V., Reese M.G., Reinert K., Remington K., Saunders R.D.C., Scheeler F., Shen H., Shue B.C., Siden-Kiamos I., Simpson M., Skupski M.P., Smith T.J., Spier E., Spradling A.C., Stapleton M., Strong R., Sun E., Svirskas R., Tector C., Turner R., Venter E., Wang A.H., Wang X., Wang Z.-Y., Wassarman D.A., Weinstock G.M., Weissenbach J., Williams S.M., Woodage T., Worley K.C., Wu D., Yang S., Yao Q.A., Ye J., Yeh R.-F., Zaveri J.S., Zhan M., Zhang G., Zhao Q., Zheng L., Zheng X.H., Zhong F.N., Zhong W., Zhou X., Zhu S.C., Zhu X., Smith H.O., Gibbs R.A., Myers E.W., Rubin G.M., Venter J.C.
    Science 287:2185-2195(2000) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: Berkeley.
  2. Cited for: GENOME REANNOTATION.
    Strain: Berkeley.
  3. "A Drosophila full-length cDNA resource."
    Stapleton M., Carlson J.W., Brokstein P., Yu C., Champe M., George R.A., Guarin H., Kronmiller B., Pacleb J.M., Park S., Wan K.H., Rubin G.M., Celniker S.E.
    Genome Biol. 3:RESEARCH0080.1-RESEARCH0080.8(2002) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
    Strain: BerkeleyImported.
    Tissue: Head1 Publication.
  4. "Intragenic Hill-Robertson interference influences selection intensity on synonymous mutations in Drosophila."
    Comeron J.M., Guthrie T.B.
    Mol. Biol. Evol. 22:2519-2530(2005) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 8-880.
    Strain: Ral1Imported.
  5. Carlson J.W., Booth B., Frise E., Park S., Wan K.H., Yu C., Celniker S.E.
    Submitted (MAR-2009) to the EMBL/GenBank/DDBJ databases
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] OF 21-711.
    Strain: Berkeley.
  6. "Identification of Hedgehog pathway components by RNAi in Drosophila cultured cells."
    Lum L., Yao S., Mozer B., Rovescalli A., Von Kessler D., Nirenberg M., Beachy P.A.
    Science 299:2039-2045(2003) [PubMed] [Europe PMC] [Abstract]
    Cited for: IDENTIFICATION.
  7. "The ihog cell-surface proteins bind Hedgehog and mediate pathway activation."
    Yao S., Lum L., Beachy P.A.
    Cell 125:343-357(2006) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, INTERACTION WITH HH, SUBCELLULAR LOCATION, DEVELOPMENTAL STAGE, DOMAIN, DISRUPTION PHENOTYPE.
  8. "Mass-spectrometric identification and relative quantification of N-linked cell surface glycoproteins."
    Wollscheid B., Bausch-Fluck D., Henderson C., O'Brien R., Bibel M., Schiess R., Aebersold R., Watts J.D.
    Nat. Biotechnol. 27:378-386(2009) [PubMed] [Europe PMC] [Abstract]
    Cited for: GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-108, IDENTIFICATION BY MASS SPECTROMETRY.
  9. Cited for: X-RAY CRYSTALLOGRAPHY (1.30 ANGSTROMS) OF 466-677 IN A COMPLEX WITH HH, SUBUNIT, HEPARIN-BINDING, MUTAGENESIS OF ARG-503; LYS-507; LYS-509 AND ARG-547.

Entry informationi

Entry nameiIHOG_DROME
AccessioniPrimary (citable) accession number: Q9VM64
Secondary accession number(s): C0PTX1, Q2XY56
Entry historyi
Integrated into UniProtKB/Swiss-Prot: September 22, 2009
Last sequence update: May 1, 2000
Last modified: June 8, 2016
This is version 138 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programDrosophila annotation project

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. Drosophila
    Drosophila: entries, gene names and cross-references to FlyBase
  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.