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Protein

Medium-wave-sensitive opsin 1

Gene

OPN1MW

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

Functioni

Visual pigments are the light-absorbing molecules that mediate vision. They consist of an apoprotein, opsin, covalently linked to cis-retinal.

Absorptioni

Abs(max)=530 nm

GO - Molecular functioni

  • G-protein coupled receptor activity Source: UniProtKB-KW
  • photoreceptor activity Source: CACAO

GO - Biological processi

  • G-protein coupled receptor signaling pathway Source: ProtInc
  • phototransduction, visible light Source: Reactome
  • positive regulation of cytokinesis Source: UniProtKB
  • protein-chromophore linkage Source: UniProtKB-KW
  • retinoid metabolic process Source: Reactome
  • visual perception Source: ProtInc
Complete GO annotation...

Keywords - Molecular functioni

G-protein coupled receptor, Photoreceptor protein, Receptor, Retinal protein, Transducer

Keywords - Biological processi

Sensory transduction, Vision

Keywords - Ligandi

Chromophore

Enzyme and pathway databases

ReactomeiREACT_160083. The retinoid cycle in cones (daylight vision).
REACT_160130. Retinoid cycle disease events.
REACT_18426. Opsins.
REACT_19231. G alpha (i) signalling events.

Names & Taxonomyi

Protein namesi
Recommended name:
Medium-wave-sensitive opsin 1
Alternative name(s):
Green cone photoreceptor pigment
Green-sensitive opsin
Short name:
GOP
Gene namesi
Name:OPN1MW
Synonyms:GCP
AND
Name:OPN1MW2
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
ProteomesiUP000005640 Componenti: Chromosome X

Organism-specific databases

HGNCiHGNC:4206. OPN1MW.
HGNC:26952. OPN1MW2.

Subcellular locationi

Topology

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Topological domaini1 – 5252ExtracellularAdd
BLAST
Transmembranei53 – 7725Helical; Name=1Sequence AnalysisAdd
BLAST
Topological domaini78 – 8912CytoplasmicAdd
BLAST
Transmembranei90 – 11526Helical; Name=2Sequence AnalysisAdd
BLAST
Topological domaini116 – 12914ExtracellularAdd
BLAST
Transmembranei130 – 14920Helical; Name=3Sequence AnalysisAdd
BLAST
Topological domaini150 – 16819CytoplasmicAdd
BLAST
Transmembranei169 – 19224Helical; Name=4Sequence AnalysisAdd
BLAST
Topological domaini193 – 21826ExtracellularAdd
BLAST
Transmembranei219 – 24628Helical; Name=5Sequence AnalysisAdd
BLAST
Topological domaini247 – 26822CytoplasmicAdd
BLAST
Transmembranei269 – 29224Helical; Name=6Sequence AnalysisAdd
BLAST
Topological domaini293 – 3008Extracellular
Transmembranei301 – 32525Helical; Name=7Sequence AnalysisAdd
BLAST
Topological domaini326 – 36439CytoplasmicAdd
BLAST

GO - Cellular componenti

  • integral component of plasma membrane Source: ProtInc
  • photoreceptor outer segment membrane Source: Reactome
  • plasma membrane Source: UniProtKB
Complete GO annotation...

Keywords - Cellular componenti

Membrane

Pathology & Biotechi

Involvement in diseasei

Colorblindness, partial, deutan series (CBD)2 Publications

The disease is caused by mutations affecting the gene represented in this entry.

Disease descriptionA color vision defect characterized by a dichromasy in which red and green are confused, without loss of luminance or shift or shortening of the spectrum. Dichromasy is due to the use of only two types of photoreceptors, blue plus red in deuteranopia and blue plus green in protanopia.

See also OMIM:303800
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Natural varianti94 – 941N → K in CBD. 1 Publication
VAR_064051
Natural varianti203 – 2031C → R in CBD and BCM. 2 Publications
VAR_004841
Natural varianti330 – 3301R → Q in CBD. 1 Publication
VAR_064053
Blue cone monochromacy (BCM)1 Publication

The disease is caused by mutations affecting the gene represented in this entry.

Disease descriptionA rare X-linked congenital stationary cone dysfunction syndrome characterized by the absence of functional long wavelength-sensitive and medium wavelength-sensitive cones in the retina. Color discrimination is severely impaired from birth, and vision is derived from the remaining preserved blue (S) cones and rod photoreceptors. BCM typically presents with reduced visual acuity, pendular nystagmus, and photophobia. Patients often have myopia.

See also OMIM:303700
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Natural varianti203 – 2031C → R in CBD and BCM. 2 Publications
VAR_004841
Cone dystrophy 5 (COD5)1 Publication

The disease is caused by mutations affecting the gene represented in this entry.

Disease descriptionA X-linked cone dystrophy. Cone dystrophies are retinal dystrophies characterized by progressive degeneration of the cone photoreceptors with preservation of rod function, as indicated by electroretinogram. However, some rod involvement may be present in some cone dystrophies, particularly at late stage. Affected individuals suffer from photophobia, loss of visual acuity, color vision and central visual field. Another sign is the absence of macular lesions for many years. Cone dystrophies are distinguished from the cone-rod dystrophies in which some loss of peripheral vision also occurs.

See also OMIM:303700
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Natural varianti177 – 1771W → R in COD5; results in protein misfolding and retention in the endoplasmic reticulum. 1 Publication
VAR_064052

Keywords - Diseasei

Disease mutation

Organism-specific databases

MIMi303700. phenotype.
303800. phenotype.
Orphaneti16. Blue cone monochromatism.
1872. Cone rod dystrophy.
319698. Partial color blindness, deutan type.
PharmGKBiPA142671229.

Polymorphism and mutation databases

BioMutaiOPN1MW.
DMDMi129215.

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 364364Medium-wave-sensitive opsin 1PRO_0000197785Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Glycosylationi34 – 341N-linked (GlcNAc...)Curated
Disulfide bondi126 ↔ 203PROSITE-ProRule annotation
Modified residuei312 – 3121N6-(retinylidene)lysine

Post-translational modificationi

Phosphorylated on some or all of the serine and threonine residues present in the C-terminal region.

Keywords - PTMi

Disulfide bond, Glycoprotein, Phosphoprotein

Proteomic databases

PaxDbiP04001.
PRIDEiP04001.

PTM databases

PhosphoSiteiP04001.

Expressioni

Tissue specificityi

The three color pigments are found in the cone photoreceptor cells.

Gene expression databases

BgeeiP04001.
CleanExiHS_OPN1MW.
HS_OPN1MW2.
ExpressionAtlasiP04001. baseline.
GenevisibleiP04001. HS.

Structurei

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1KPWmodel-A1-364[»]
ProteinModelPortaliP04001.
SMRiP04001. Positions 23-334.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Belongs to the G-protein coupled receptor 1 family. Opsin subfamily.PROSITE-ProRule annotation

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiNOG240324.
GeneTreeiENSGT00760000118977.
HOGENOMiHOG000253932.
HOVERGENiHBG107442.
InParanoidiP04001.
KOiK04251.
OMAiCCITPLS.
OrthoDBiEOG72NRQJ.
PhylomeDBiP04001.
TreeFamiTF324998.

Family and domain databases

InterProiIPR000276. GPCR_Rhodpsn.
IPR017452. GPCR_Rhodpsn_7TM.
IPR001760. Opsin.
IPR000378. Opsin_red/grn.
IPR027430. Retinal_BS.
[Graphical view]
PfamiPF00001. 7tm_1. 1 hit.
[Graphical view]
PRINTSiPR00237. GPCRRHODOPSN.
PR00238. OPSIN.
PR00575. OPSINREDGRN.
PROSITEiPS00237. G_PROTEIN_RECEP_F1_1. 1 hit.
PS50262. G_PROTEIN_RECEP_F1_2. 1 hit.
PS00238. OPSIN. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

P04001-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MAQQWSLQRL AGRHPQDSYE DSTQSSIFTY TNSNSTRGPF EGPNYHIAPR
60 70 80 90 100
WVYHLTSVWM IFVVIASVFT NGLVLAATMK FKKLRHPLNW ILVNLAVADL
110 120 130 140 150
AETVIASTIS VVNQVYGYFV LGHPMCVLEG YTVSLCGITG LWSLAIISWE
160 170 180 190 200
RWMVVCKPFG NVRFDAKLAI VGIAFSWIWA AVWTAPPIFG WSRYWPHGLK
210 220 230 240 250
TSCGPDVFSG SSYPGVQSYM IVLMVTCCIT PLSIIVLCYL QVWLAIRAVA
260 270 280 290 300
KQQKESESTQ KAEKEVTRMV VVMVLAFCFC WGPYAFFACF AAANPGYPFH
310 320 330 340 350
PLMAALPAFF AKSATIYNPV IYVFMNRQFR NCILQLFGKK VDDGSELSSA
360
SKTEVSSVSS VSPA
Length:364
Mass (Da):40,584
Last modified:October 23, 1986 - v1
Checksum:iA98D046958C72AE9
GO

Natural variant

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Natural varianti94 – 941N → K in CBD. 1 Publication
VAR_064051
Natural varianti177 – 1771W → R in COD5; results in protein misfolding and retention in the endoplasmic reticulum. 1 Publication
VAR_064052
Natural varianti203 – 2031C → R in CBD and BCM. 2 Publications
VAR_004841
Natural varianti330 – 3301R → Q in CBD. 1 Publication
VAR_064053

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
K03494
, M13306, K03490, K03491, K03492, K03493 Genomic DNA. Translation: AAB59503.1.
K03497, K03495, K03496 Genomic DNA. Translation: AAB59525.1. Sequence problems.
AC092402 Genomic DNA. No translation available.
Z46936 Genomic DNA. No translation available.
CCDSiCCDS14743.1.
CCDS35447.1.
PIRiA03158. OOHUG.
RefSeqiNP_000504.1. NM_000513.2.
NP_001041646.1. NM_001048181.2.
XP_003960138.1. XM_003960089.3.
XP_005276782.1. XM_005276725.2.
UniGeneiHs.247787.
Hs.571751.

Genome annotation databases

EnsembliENST00000369929; ENSP00000358945; ENSG00000166160.
ENST00000595290; ENSP00000472316; ENSG00000268221.
ENST00000599405; ENSP00000469970; ENSG00000269433.
GeneIDi101060233.
2652.
728458.
KEGGihsa:101060233.
hsa:2652.
hsa:728458.
UCSCiuc004fkb.3. human.

Cross-referencesi

Web resourcesi

Mutations of the color pigment genes

Retina International's Scientific Newsletter

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
K03494
, M13306, K03490, K03491, K03492, K03493 Genomic DNA. Translation: AAB59503.1.
K03497, K03495, K03496 Genomic DNA. Translation: AAB59525.1. Sequence problems.
AC092402 Genomic DNA. No translation available.
Z46936 Genomic DNA. No translation available.
CCDSiCCDS14743.1.
CCDS35447.1.
PIRiA03158. OOHUG.
RefSeqiNP_000504.1. NM_000513.2.
NP_001041646.1. NM_001048181.2.
XP_003960138.1. XM_003960089.3.
XP_005276782.1. XM_005276725.2.
UniGeneiHs.247787.
Hs.571751.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1KPWmodel-A1-364[»]
ProteinModelPortaliP04001.
SMRiP04001. Positions 23-334.
ModBaseiSearch...
MobiDBiSearch...

Protein family/group databases

GPCRDBiSearch...

PTM databases

PhosphoSiteiP04001.

Polymorphism and mutation databases

BioMutaiOPN1MW.
DMDMi129215.

Proteomic databases

PaxDbiP04001.
PRIDEiP04001.

Protocols and materials databases

DNASUi2652.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000369929; ENSP00000358945; ENSG00000166160.
ENST00000595290; ENSP00000472316; ENSG00000268221.
ENST00000599405; ENSP00000469970; ENSG00000269433.
GeneIDi101060233.
2652.
728458.
KEGGihsa:101060233.
hsa:2652.
hsa:728458.
UCSCiuc004fkb.3. human.

Organism-specific databases

CTDi2652.
728458.
GeneCardsiGC0XP153448.
GC0XP153485.
GeneReviewsiOPN1MW.
H-InvDBHIX0056274.
HGNCiHGNC:4206. OPN1MW.
HGNC:26952. OPN1MW2.
MIMi300821. gene.
303700. phenotype.
303800. phenotype.
neXtProtiNX_P04001.
Orphaneti16. Blue cone monochromatism.
1872. Cone rod dystrophy.
319698. Partial color blindness, deutan type.
PharmGKBiPA142671229.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiNOG240324.
GeneTreeiENSGT00760000118977.
HOGENOMiHOG000253932.
HOVERGENiHBG107442.
InParanoidiP04001.
KOiK04251.
OMAiCCITPLS.
OrthoDBiEOG72NRQJ.
PhylomeDBiP04001.
TreeFamiTF324998.

Enzyme and pathway databases

ReactomeiREACT_160083. The retinoid cycle in cones (daylight vision).
REACT_160130. Retinoid cycle disease events.
REACT_18426. Opsins.
REACT_19231. G alpha (i) signalling events.

Miscellaneous databases

GeneWikiiOPN1MW.
NextBioi10480.
PROiP04001.
SOURCEiSearch...

Gene expression databases

BgeeiP04001.
CleanExiHS_OPN1MW.
HS_OPN1MW2.
ExpressionAtlasiP04001. baseline.
GenevisibleiP04001. HS.

Family and domain databases

InterProiIPR000276. GPCR_Rhodpsn.
IPR017452. GPCR_Rhodpsn_7TM.
IPR001760. Opsin.
IPR000378. Opsin_red/grn.
IPR027430. Retinal_BS.
[Graphical view]
PfamiPF00001. 7tm_1. 1 hit.
[Graphical view]
PRINTSiPR00237. GPCRRHODOPSN.
PR00238. OPSIN.
PR00575. OPSINREDGRN.
PROSITEiPS00237. G_PROTEIN_RECEP_F1_1. 1 hit.
PS50262. G_PROTEIN_RECEP_F1_2. 1 hit.
PS00238. OPSIN. 1 hit.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "Molecular genetics of human color vision: the genes encoding blue, green, and red pigments."
    Nathans J., Thomas D., Hogness D.S.
    Science 232:193-202(1986) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
    Tissue: Retinal cone cell.
  2. "The DNA sequence of the human X chromosome."
    Ross M.T., Grafham D.V., Coffey A.J., Scherer S., McLay K., Muzny D., Platzer M., Howell G.R., Burrows C., Bird C.P., Frankish A., Lovell F.L., Howe K.L., Ashurst J.L., Fulton R.S., Sudbrak R., Wen G., Jones M.C.
    , Hurles M.E., Andrews T.D., Scott C.E., Searle S., Ramser J., Whittaker A., Deadman R., Carter N.P., Hunt S.E., Chen R., Cree A., Gunaratne P., Havlak P., Hodgson A., Metzker M.L., Richards S., Scott G., Steffen D., Sodergren E., Wheeler D.A., Worley K.C., Ainscough R., Ambrose K.D., Ansari-Lari M.A., Aradhya S., Ashwell R.I., Babbage A.K., Bagguley C.L., Ballabio A., Banerjee R., Barker G.E., Barlow K.F., Barrett I.P., Bates K.N., Beare D.M., Beasley H., Beasley O., Beck A., Bethel G., Blechschmidt K., Brady N., Bray-Allen S., Bridgeman A.M., Brown A.J., Brown M.J., Bonnin D., Bruford E.A., Buhay C., Burch P., Burford D., Burgess J., Burrill W., Burton J., Bye J.M., Carder C., Carrel L., Chako J., Chapman J.C., Chavez D., Chen E., Chen G., Chen Y., Chen Z., Chinault C., Ciccodicola A., Clark S.Y., Clarke G., Clee C.M., Clegg S., Clerc-Blankenburg K., Clifford K., Cobley V., Cole C.G., Conquer J.S., Corby N., Connor R.E., David R., Davies J., Davis C., Davis J., Delgado O., Deshazo D., Dhami P., Ding Y., Dinh H., Dodsworth S., Draper H., Dugan-Rocha S., Dunham A., Dunn M., Durbin K.J., Dutta I., Eades T., Ellwood M., Emery-Cohen A., Errington H., Evans K.L., Faulkner L., Francis F., Frankland J., Fraser A.E., Galgoczy P., Gilbert J., Gill R., Gloeckner G., Gregory S.G., Gribble S., Griffiths C., Grocock R., Gu Y., Gwilliam R., Hamilton C., Hart E.A., Hawes A., Heath P.D., Heitmann K., Hennig S., Hernandez J., Hinzmann B., Ho S., Hoffs M., Howden P.J., Huckle E.J., Hume J., Hunt P.J., Hunt A.R., Isherwood J., Jacob L., Johnson D., Jones S., de Jong P.J., Joseph S.S., Keenan S., Kelly S., Kershaw J.K., Khan Z., Kioschis P., Klages S., Knights A.J., Kosiura A., Kovar-Smith C., Laird G.K., Langford C., Lawlor S., Leversha M., Lewis L., Liu W., Lloyd C., Lloyd D.M., Loulseged H., Loveland J.E., Lovell J.D., Lozado R., Lu J., Lyne R., Ma J., Maheshwari M., Matthews L.H., McDowall J., McLaren S., McMurray A., Meidl P., Meitinger T., Milne S., Miner G., Mistry S.L., Morgan M., Morris S., Mueller I., Mullikin J.C., Nguyen N., Nordsiek G., Nyakatura G., O'dell C.N., Okwuonu G., Palmer S., Pandian R., Parker D., Parrish J., Pasternak S., Patel D., Pearce A.V., Pearson D.M., Pelan S.E., Perez L., Porter K.M., Ramsey Y., Reichwald K., Rhodes S., Ridler K.A., Schlessinger D., Schueler M.G., Sehra H.K., Shaw-Smith C., Shen H., Sheridan E.M., Shownkeen R., Skuce C.D., Smith M.L., Sotheran E.C., Steingruber H.E., Steward C.A., Storey R., Swann R.M., Swarbreck D., Tabor P.E., Taudien S., Taylor T., Teague B., Thomas K., Thorpe A., Timms K., Tracey A., Trevanion S., Tromans A.C., d'Urso M., Verduzco D., Villasana D., Waldron L., Wall M., Wang Q., Warren J., Warry G.L., Wei X., West A., Whitehead S.L., Whiteley M.N., Wilkinson J.E., Willey D.L., Williams G., Williams L., Williamson A., Williamson H., Wilming L., Woodmansey R.L., Wray P.W., Yen J., Zhang J., Zhou J., Zoghbi H., Zorilla S., Buck D., Reinhardt R., Poustka A., Rosenthal A., Lehrach H., Meindl A., Minx P.J., Hillier L.W., Willard H.F., Wilson R.K., Waterston R.H., Rice C.M., Vaudin M., Coulson A., Nelson D.L., Weinstock G., Sulston J.E., Durbin R.M., Hubbard T., Gibbs R.A., Beck S., Rogers J., Bentley D.R.
    Nature 434:325-337(2005) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
  3. Buck D.
    Submitted (DEC-1994) to the EMBL/GenBank/DDBJ databases
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 194-364.
  4. "Molecular biology of the visual pigments."
    Applebury M.L., Hargrave P.A.
    Vision Res. 26:1881-1895(1986) [PubMed] [Europe PMC] [Abstract]
    Cited for: REVIEW.
  5. "Defective colour vision associated with a missense mutation in the human green visual pigment gene."
    Winderickx J., Sanocki E., Lindsey D.T., Teller D.Y., Motulsky A.G., Deeb S.S.
    Nat. Genet. 1:251-256(1992) [PubMed] [Europe PMC] [Abstract]
    Cited for: VARIANT CBD ARG-203.
  6. "Gene conversion between red and defective green opsin gene in blue cone monochromacy."
    Reyniers E., Van Thienen M.N., Meire F., De Boulle K., Devries K., Kestelijn P., Willems P.J.
    Genomics 29:323-328(1995) [PubMed] [Europe PMC] [Abstract]
    Cited for: VARIANT BCM ARG-203.
  7. "Novel missense mutations in red/green opsin genes in congenital color-vision deficiencies."
    Ueyama H., Kuwayama S., Imai H., Tanabe S., Oda S., Nishida Y., Wada A., Shichida Y., Yamade S.
    Biochem. Biophys. Res. Commun. 294:205-209(2002) [PubMed] [Europe PMC] [Abstract]
    Cited for: VARIANTS CBD LYS-94 AND GLN-330.
  8. Cited for: VARIANT COD5 ARG-177, CHARACTERIZATION OF VARIANT COD5 ARG-177.

Entry informationi

Entry nameiOPSG_HUMAN
AccessioniPrimary (citable) accession number: P04001
Entry historyi
Integrated into UniProtKB/Swiss-Prot: October 23, 1986
Last sequence update: October 23, 1986
Last modified: June 24, 2015
This is version 152 of the entry and version 1 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

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. 7-transmembrane G-linked receptors
    List of 7-transmembrane G-linked receptor entries
  2. Human chromosome X
    Human chromosome X: 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. SIMILARITY comments
    Index of protein domains and families

External Data

Dasty 3

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 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.