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Protein

E3 ubiquitin-protein ligase UBR1

Gene

UBR1

Organism
Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Ubiquitin ligase protein which is a component of the N-end rule pathway. Recognizes and binds to proteins bearing specific N-terminal residues that are destabilizing according to the N-end rule, leading to their ubiquitination and subsequent degradation.

Pathwayi: protein ubiquitination

This protein is involved in the pathway protein ubiquitination, which is part of Protein modification.
View all proteins of this organism that are known to be involved in the pathway protein ubiquitination and in Protein modification.

Regions

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Zinc fingeri121 – 19474UBR-typePROSITE-ProRule annotationAdd
BLAST
Zinc fingeri1220 – 1324105RING-type; atypicalAdd
BLAST

GO - Molecular functioni

  • ligase activity Source: UniProtKB-KW
  • ubiquitin-protein transferase activity Source: SGD
  • zinc ion binding Source: InterPro

GO - Biological processi

  • cytoplasm-associated proteasomal ubiquitin-dependent protein catabolic process Source: SGD
  • ER-associated ubiquitin-dependent protein catabolic process Source: SGD
  • protein monoubiquitination Source: SGD
  • protein polyubiquitination Source: SGD
  • regulation of dipeptide transport Source: SGD
  • ribosome-associated ubiquitin-dependent protein catabolic process Source: SGD
  • ubiquitin-dependent protein catabolic process via the N-end rule pathway Source: SGD
Complete GO annotation...

Keywords - Molecular functioni

Ligase

Keywords - Biological processi

Ubl conjugation pathway

Keywords - Ligandi

Metal-binding, Zinc

Enzyme and pathway databases

BioCyciYEAST:G3O-30874-MONOMER.
BRENDAi2.3.2.B9. 984.
6.3.2.19. 984.
UniPathwayiUPA00143.

Names & Taxonomyi

Protein namesi
Recommended name:
E3 ubiquitin-protein ligase UBR1 (EC:6.3.2.-)
Alternative name(s):
N-end-recognizing protein
N-recognin-1
Gene namesi
Name:UBR1
Synonyms:PTR1
Ordered Locus Names:YGR184C
ORF Names:G7168
OrganismiSaccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
Taxonomic identifieri559292 [NCBI]
Taxonomic lineageiEukaryotaFungiDikaryaAscomycotaSaccharomycotinaSaccharomycetesSaccharomycetalesSaccharomycetaceaeSaccharomyces
Proteomesi
  • UP000002311 Componenti: Chromosome VII

Organism-specific databases

EuPathDBiFungiDB:YGR184C.
SGDiS000003416. UBR1.

Subcellular locationi

GO - Cellular componenti

  • cytoplasm Source: SGD
Complete GO annotation...

Pathology & Biotechi

Mutagenesis

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Mutagenesisi1168 – 11681K → S: Impairs interaction with UBC2, but does not affect degradation of N-end rule substrates. 1 Publication
Mutagenesisi1169 – 11691R → L: Impairs interaction with UBC2, but does not affect degradation of N-end rule substrates. 1 Publication
Mutagenesisi1173 – 11731K → A: Impairs interaction with UBC2, but does not affect degradation of N-end rule substrates. 1 Publication
Mutagenesisi1220 – 12201C → S: No effect on interaction with UBC2, but inhibits degradation of N-end rule substrates. 1 Publication
Mutagenesisi1223 – 12231C → S: No effect on interaction with UBC2, but inhibits degradation of N-end rule substrates. 1 Publication
Mutagenesisi1295 – 12951C → S: No effect on interaction with UBC2, but inhibits degradation of N-end rule substrates. 1 Publication
Mutagenesisi1297 – 12971H → A: No effect on interaction with UBC2, but inhibits degradation of N-end rule substrates. 1 Publication
Mutagenesisi1320 – 13201C → S: No effect on interaction with UBC2, but inhibits degradation of N-end rule substrates. 1 Publication

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 19501950E3 ubiquitin-protein ligase UBR1PRO_0000056135Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei296 – 2961PhosphoserineCombined sources
Modified residuei300 – 3001PhosphoserineCombined sources
Modified residuei1938 – 19381PhosphoserineCombined sources

Keywords - PTMi

Phosphoprotein

Proteomic databases

MaxQBiP19812.
PeptideAtlasiP19812.

PTM databases

iPTMnetiP19812.

Interactioni

Subunit structurei

Interacts with UBC2. Interacts with RPN2, RPT1 and RPT6 from the 26S proteasome.2 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
RAD6P061043EBI-19909,EBI-19722
RPN2P325652EBI-19909,EBI-15919
RPT1P332992EBI-19909,EBI-13910
RPT6Q019394EBI-19909,EBI-13914

Protein-protein interaction databases

BioGridi33436. 158 interactions.
DIPiDIP-2517N.
IntActiP19812. 10 interactions.
MINTiMINT-596541.

Structurei

Secondary structure

1
1950
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Beta strandi132 – 1365Combined sources
Turni137 – 1393Combined sources
Beta strandi140 – 1423Combined sources
Turni149 – 1513Combined sources
Helixi154 – 1574Combined sources
Beta strandi162 – 1665Combined sources
Beta strandi169 – 1746Combined sources
Helixi180 – 1823Combined sources
Beta strandi183 – 1853Combined sources
Helixi190 – 1923Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
3NIHX-ray2.10A115-194[»]
3NIIX-ray2.10A115-194[»]
3NIJX-ray2.10A115-194[»]
3NIKX-ray1.85A/B/D/F115-194[»]
3NILX-ray1.75A/B/D/F115-194[»]
3NIMX-ray2.00A/B/D/F115-194[»]
3NINX-ray2.10A/B115-194[»]
3NISX-ray1.68A/B/D/F115-194[»]
3NITX-ray2.60A107-194[»]
ProteinModelPortaliP19812.
SMRiP19812. Positions 115-194.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP19812.

Family & Domainsi

Region

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Regioni1117 – 1219103Interaction with UBC2Add
BLAST

Domaini

The RING-H2 zinc finger is an atypical RING finger with a His ligand in place of the fourth Cys of the classical motif.

Sequence similaritiesi

Belongs to the UBR1 family.Curated
Contains 1 RING-type zinc finger.Curated
Contains 1 UBR-type zinc finger.PROSITE-ProRule annotation

Zinc finger

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Zinc fingeri121 – 19474UBR-typePROSITE-ProRule annotationAdd
BLAST
Zinc fingeri1220 – 1324105RING-type; atypicalAdd
BLAST

Keywords - Domaini

Zinc-finger

Phylogenomic databases

GeneTreeiENSGT00530000063055.
HOGENOMiHOG000142344.
InParanoidiP19812.
KOiK10625.
OMAiTIRMNEI.
OrthoDBiEOG76X67D.

Family and domain databases

InterProiIPR003126. Znf_UBR.
[Graphical view]
PfamiPF02207. zf-UBR. 1 hit.
[Graphical view]
SMARTiSM00396. ZnF_UBR1. 1 hit.
[Graphical view]
PROSITEiPS51157. ZF_UBR. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

P19812-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MSVADDDLGS LQGHIRRTLR SIHNLPYFRY TRGPTERADM SRALKEFIYR
60 70 80 90 100
YLYFVISNSG ENLPTLFNAH PKQKLSNPEL TVFPDSLEDA VDIDKITSQQ
110 120 130 140 150
TIPFYKIDES RIGDVHKHTG RNCGRKFKIG EPLYRCHECG CDDTCVLCIH
160 170 180 190 200
CFNPKDHVNH HVCTDICTEF TSGICDCGDE EAWNSPLHCK AEEQENDISE
210 220 230 240 250
DPATNADIKE EDVWNDSVNI ALVELVLAEV FDYFIDVFNQ NIEPLPTIQK
260 270 280 290 300
DITIKLREMT QQGKMYERAQ FLNDLKYEND YMFDGTTTAK TSPSNSPEAS
310 320 330 340 350
PSLAKIDPEN YTVIIYNDEY HNYSQATTAL RQGVPDNVHI DLLTSRIDGE
360 370 380 390 400
GRAMLKCSQD LSSVLGGFFA VQTNGLSATL TSWSEYLHQE TCKYIILWIT
410 420 430 440 450
HCLNIPNSSF QTTFRNMMGK TLCSEYLNAT ECRDMTPVVE KYFSNKFDKN
460 470 480 490 500
DPYRYIDLSI LADGNQIPLG HHKILPESST HSLSPLINDV ETPTSRTYSN
510 520 530 540 550
TRLQHILYFD NRYWKRLRKD IQNVIIPTLA SSNLYKPIFC QQVVEIFNHI
560 570 580 590 600
TRSVAYMDRE PQLTAIRECV VQLFTCPTNA KNIFENQSFL DIVWSIIDIF
610 620 630 640 650
KEFCKVEGGV LIWQRVQKSN LTKSYSISFK QGLYTVETLL SKVHDPNIPL
660 670 680 690 700
RPKEIISLLT LCKLFNGAWK IKRKEGEHVL HEDQNFISYL EYTTSIYSII
710 720 730 740 750
QTAEKVSEKS KDSIDSKLFL NAIRIISSFL GNRSLTYKLI YDSHEVIKFS
760 770 780 790 800
VSHERVAFMN PLQTMLSFLI EKVSLKDAYE ALEDCSDFLK ISDFSLRSVV
810 820 830 840 850
LCSQIDVGFW VRNGMSVLHQ ASYYKNNPEL GSYSRDIHLN QLAILWERDD
860 870 880 890 900
IPRIIYNILD RWELLDWFTG EVDYQHTVYE DKISFIIQQF IAFIYQILTE
910 920 930 940 950
RQYFKTFSSL KDRRMDQIKN SIIYNLYMKP LSYSKLLRSV PDYLTEDTTE
960 970 980 990 1000
FDEALEEVSV FVEPKGLADN GVFKLKASLY AKVDPLKLLN LENEFESSAT
1010 1020 1030 1040 1050
IIKSHLAKDK DEIAKVVLIP QVSIKQLDKD ALNLGAFTRN TVFAKVVYKL
1060 1070 1080 1090 1100
LQVCLDMEDS TFLNELLHLV HGIFRDDELI NGKDSIPEAY LSKPICNLLL
1110 1120 1130 1140 1150
SIANAKSDVF SESIVRKADY LLEKMIMKKP NELFESLIAS FGNQYVNDYK
1160 1170 1180 1190 1200
DKKLRQGVNL QETEKERKRR LAKKHQARLL AKFNNQQTKF MKEHESEFDE
1210 1220 1230 1240 1250
QDNDVDMVGE KVYESEDFTC ALCQDSSSTD FFVIPAYHDH SPIFRPGNIF
1260 1270 1280 1290 1300
NPNEFMPMWD GFYNDDEKQA YIDDDVLEAL KENGSCGSRK VFVSCNHHIH
1310 1320 1330 1340 1350
HNCFKRYVQK KRFSSNAFIC PLCQTFSNCT LPLCQTSKAN TGLSLDMFLE
1360 1370 1380 1390 1400
SELSLDTLSR LFKPFTEENY RTINSIFSLM ISQCQGFDKA VRKRANFSHK
1410 1420 1430 1440 1450
DVSLILSVHW ANTISMLEIA SRLEKPYSIS FFRSREQKYK TLKNILVCIM
1460 1470 1480 1490 1500
LFTFVIGKPS MEFEPYPQQP DTVWNQNQLF QYIVRSALFS PVSLRQTVTE
1510 1520 1530 1540 1550
ALTTFSRQFL RDFLQGLSDA EQVTKLYAKA SKIGDVLKVS EQMLFALRTI
1560 1570 1580 1590 1600
SDVRMEGLDS ESIIYDLAYT FLLKSLLPTI RRCLVFIKVL HELVKDSENE
1610 1620 1630 1640 1650
TLVINGHEVE EELEFEDTAE FVNKALKMIT EKESLVDLLT TQESIVSHPY
1660 1670 1680 1690 1700
LENIPYEYCG IIKLIDLSKY LNTYVTQSKE IKLREERSQH MKNADNRLDF
1710 1720 1730 1740 1750
KICLTCGVKV HLRADRHEMT KHLNKNCFKP FGAFLMPNSS EVCLHLTQPP
1760 1770 1780 1790 1800
SNIFISAPYL NSHGEVGRNA MRRGDLTTLN LKRYEHLNRL WINNEIPGYI
1810 1820 1830 1840 1850
SRVMGDEFRV TILSNGFLFA FNREPRPRRI PPTDEDDEDM EEGEDGFFTE
1860 1870 1880 1890 1900
GNDEMDVDDE TGQAANLFGV GAEGIAGGGV RDFFQFFENF RNTLQPQGNG
1910 1920 1930 1940 1950
DDDAPQNPPP ILQFLGPQFD GATIIRNTNP RNLDEDDSDD NDDSDEREIW
Length:1,950
Mass (Da):224,838
Last modified:February 1, 1991 - v1
Checksum:i33E4CD3A031AF523
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X53747 Genomic DNA. Translation: CAA37779.1.
X99074 Genomic DNA. Translation: CAA67528.1.
Z72969 Genomic DNA. Translation: CAA97210.1.
BK006941 Genomic DNA. Translation: DAA08278.1.
PIRiS12332.
RefSeqiNP_011700.1. NM_001181313.1.

Genome annotation databases

EnsemblFungiiYGR184C; YGR184C; YGR184C.
GeneIDi853096.
KEGGisce:YGR184C.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X53747 Genomic DNA. Translation: CAA37779.1.
X99074 Genomic DNA. Translation: CAA67528.1.
Z72969 Genomic DNA. Translation: CAA97210.1.
BK006941 Genomic DNA. Translation: DAA08278.1.
PIRiS12332.
RefSeqiNP_011700.1. NM_001181313.1.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
3NIHX-ray2.10A115-194[»]
3NIIX-ray2.10A115-194[»]
3NIJX-ray2.10A115-194[»]
3NIKX-ray1.85A/B/D/F115-194[»]
3NILX-ray1.75A/B/D/F115-194[»]
3NIMX-ray2.00A/B/D/F115-194[»]
3NINX-ray2.10A/B115-194[»]
3NISX-ray1.68A/B/D/F115-194[»]
3NITX-ray2.60A107-194[»]
ProteinModelPortaliP19812.
SMRiP19812. Positions 115-194.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi33436. 158 interactions.
DIPiDIP-2517N.
IntActiP19812. 10 interactions.
MINTiMINT-596541.

PTM databases

iPTMnetiP19812.

Proteomic databases

MaxQBiP19812.
PeptideAtlasiP19812.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblFungiiYGR184C; YGR184C; YGR184C.
GeneIDi853096.
KEGGisce:YGR184C.

Organism-specific databases

EuPathDBiFungiDB:YGR184C.
SGDiS000003416. UBR1.

Phylogenomic databases

GeneTreeiENSGT00530000063055.
HOGENOMiHOG000142344.
InParanoidiP19812.
KOiK10625.
OMAiTIRMNEI.
OrthoDBiEOG76X67D.

Enzyme and pathway databases

UniPathwayiUPA00143.
BioCyciYEAST:G3O-30874-MONOMER.
BRENDAi2.3.2.B9. 984.
6.3.2.19. 984.

Miscellaneous databases

EvolutionaryTraceiP19812.
NextBioi973087.
PROiP19812.

Family and domain databases

InterProiIPR003126. Znf_UBR.
[Graphical view]
PfamiPF02207. zf-UBR. 1 hit.
[Graphical view]
SMARTiSM00396. ZnF_UBR1. 1 hit.
[Graphical view]
PROSITEiPS51157. ZF_UBR. 1 hit.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "The recognition component of the N-end rule pathway."
    Bartel B., Wuenning I., Varshavsky A.
    EMBO J. 9:3179-3189(1990) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
    Strain: S288c / GRF88.
  2. "DNA sequence analysis of a 23,002 bp DNA fragment of the right arm of Saccharomyces cerevisiae chromosome VII."
    Arroyo J., Garcia-Gonzalez M., Garcia-Saez M.I., Sanchez-Perez M., Nombela C.
    Yeast 13:357-363(1997) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
    Strain: ATCC 204508 / S288c.
  3. "The nucleotide sequence of Saccharomyces cerevisiae chromosome VII."
    Tettelin H., Agostoni-Carbone M.L., Albermann K., Albers M., Arroyo J., Backes U., Barreiros T., Bertani I., Bjourson A.J., Brueckner M., Bruschi C.V., Carignani G., Castagnoli L., Cerdan E., Clemente M.L., Coblenz A., Coglievina M., Coissac E.
    , Defoor E., Del Bino S., Delius H., Delneri D., de Wergifosse P., Dujon B., Durand P., Entian K.-D., Eraso P., Escribano V., Fabiani L., Fartmann B., Feroli F., Feuermann M., Frontali L., Garcia-Gonzalez M., Garcia-Saez M.I., Goffeau A., Guerreiro P., Hani J., Hansen M., Hebling U., Hernandez K., Heumann K., Hilger F., Hofmann B., Indge K.J., James C.M., Klima R., Koetter P., Kramer B., Kramer W., Lauquin G., Leuther H., Louis E.J., Maillier E., Marconi A., Martegani E., Mazon M.J., Mazzoni C., McReynolds A.D.K., Melchioretto P., Mewes H.-W., Minenkova O., Mueller-Auer S., Nawrocki A., Netter P., Neu R., Nombela C., Oliver S.G., Panzeri L., Paoluzi S., Plevani P., Portetelle D., Portillo F., Potier S., Purnelle B., Rieger M., Riles L., Rinaldi T., Robben J., Rodrigues-Pousada C., Rodriguez-Belmonte E., Rodriguez-Torres A.M., Rose M., Ruzzi M., Saliola M., Sanchez-Perez M., Schaefer B., Schaefer M., Scharfe M., Schmidheini T., Schreer A., Skala J., Souciet J.-L., Steensma H.Y., Talla E., Thierry A., Vandenbol M., van der Aart Q.J.M., Van Dyck L., Vanoni M., Verhasselt P., Voet M., Volckaert G., Wambutt R., Watson M.D., Weber N., Wedler E., Wedler H., Wipfli P., Wolf K., Wright L.F., Zaccaria P., Zimmermann M., Zollner A., Kleine K.
    Nature 387:81-84(1997) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: ATCC 204508 / S288c.
  4. Cited for: GENOME REANNOTATION.
    Strain: ATCC 204508 / S288c.
  5. "The E2-E3 interaction in the N-end rule pathway: the RING-H2 finger of E3 is required for the synthesis of multiubiquitin chain."
    Xie Y., Varshavsky A.
    EMBO J. 18:6832-6844(1999) [PubMed] [Europe PMC] [Abstract]
    Cited for: INTERACTION WITH UBC2, MUTAGENESIS OF LYS-1168; ARG-1169; LYS-1173; CYS-1220; CYS-1223; CYS-1295; HIS-1297 AND CYS-1320.
  6. "Physical association of ubiquitin ligases and the 26S proteasome."
    Xie Y., Varshavsky A.
    Proc. Natl. Acad. Sci. U.S.A. 97:2497-2502(2000) [PubMed] [Europe PMC] [Abstract]
    Cited for: INTERACTION WITH RPN2; RPT1 AND RPT6.
  7. "Large-scale phosphorylation analysis of alpha-factor-arrested Saccharomyces cerevisiae."
    Li X., Gerber S.A., Rudner A.D., Beausoleil S.A., Haas W., Villen J., Elias J.E., Gygi S.P.
    J. Proteome Res. 6:1190-1197(2007) [PubMed] [Europe PMC] [Abstract]
    Cited for: PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT SER-296 AND SER-300, IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
    Strain: ADR376.
  8. "A multidimensional chromatography technology for in-depth phosphoproteome analysis."
    Albuquerque C.P., Smolka M.B., Payne S.H., Bafna V., Eng J., Zhou H.
    Mol. Cell. Proteomics 7:1389-1396(2008) [PubMed] [Europe PMC] [Abstract]
    Cited for: PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT SER-296, IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
  9. "Global analysis of Cdk1 substrate phosphorylation sites provides insights into evolution."
    Holt L.J., Tuch B.B., Villen J., Johnson A.D., Gygi S.P., Morgan D.O.
    Science 325:1682-1686(2009) [PubMed] [Europe PMC] [Abstract]
    Cited for: PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT SER-296; SER-300 AND SER-1938, IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
  10. Cited for: IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].

Entry informationi

Entry nameiUBR1_YEAST
AccessioniPrimary (citable) accession number: P19812
Secondary accession number(s): D6VUW7
Entry historyi
Integrated into UniProtKB/Swiss-Prot: February 1, 1991
Last sequence update: February 1, 1991
Last modified: May 11, 2016
This is version 151 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programFungal Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. PATHWAY comments
    Index of metabolic and biosynthesis pathways
  2. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  3. SIMILARITY comments
    Index of protein domains and families
  4. Yeast
    Yeast (Saccharomyces cerevisiae): entries, gene names and cross-references to SGD
  5. Yeast chromosome VII
    Yeast (Saccharomyces cerevisiae) chromosome VII: entries and gene names

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.