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Protein

MOB kinase activator 1A

Gene

MOB1A

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

Functioni

Activator of LATS1/2 in the Hippo signaling pathway which plays a pivotal role in organ size control and tumor suppression by restricting proliferation and promoting apoptosis. The core of this pathway is composed of a kinase cascade wherein STK3/MST2 and STK4/MST1, in complex with its regulatory protein SAV1, phosphorylates and activates LATS1/2 in complex with its regulatory protein MOB1, which in turn phosphorylates and inactivates YAP1 oncoprotein and WWTR1/TAZ. Phosphorylation of YAP1 by LATS1/2 inhibits its translocation into the nucleus to regulate cellular genes important for cell proliferation, cell death, and cell migration. Stimulates the kinase activity of STK38 and STK38L. Acts cooperatively with STK3/MST2 to activate STK38.3 Publications

Sites

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Metal bindingi79 – 791Zinc
Metal bindingi84 – 841Zinc
Metal bindingi161 – 1611Zinc
Metal bindingi166 – 1661Zinc

GO - Molecular functioni

  1. metal ion binding Source: UniProtKB-KW

GO - Biological processi

  1. hippo signaling Source: UniProtKB
Complete GO annotation...

Keywords - Ligandi

Metal-binding, Zinc

Enzyme and pathway databases

ReactomeiREACT_118607. Signaling by Hippo.

Names & Taxonomyi

Protein namesi
Recommended name:
MOB kinase activator 1A
Alternative name(s):
Mob1 alpha
Short name:
Mob1A
Mob1 homolog 1B
Mps one binder kinase activator-like 1B
Gene namesi
Name:MOB1A
Synonyms:C2orf6, MOB4B, MOBK1B, MOBKL1B
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
ProteomesiUP000005640: Chromosome 2

Organism-specific databases

HGNCiHGNC:16015. MOB1A.

Subcellular locationi

GO - Cellular componenti

  1. cytosol Source: Reactome
  2. extracellular vesicular exosome Source: UniProtKB
Complete GO annotation...

Pathology & Biotechi

Organism-specific databases

PharmGKBiPA25894.

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Initiator methioninei1 – 11Removed2 Publications
Chaini2 – 216215MOB kinase activator 1APRO_0000193566Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei2 – 21N-acetylserine2 Publications
Modified residuei12 – 121Phosphothreonine1 Publication
Modified residuei35 – 351Phosphothreonine1 Publication
Modified residuei74 – 741Phosphothreonine; by STK3/MST21 Publication
Modified residuei181 – 1811Phosphothreonine1 Publication

Post-translational modificationi

Phosphorylated by STK3/MST2 and STK4/MST1 and this phosphorylation enhances its binding to LATS1.3 Publications

Keywords - PTMi

Acetylation, Phosphoprotein

Proteomic databases

MaxQBiQ9H8S9.
PaxDbiQ9H8S9.
PRIDEiQ9H8S9.

2D gel databases

OGPiQ9H8S9.

PTM databases

PhosphoSiteiQ9H8S9.

Expressioni

Tissue specificityi

Adrenal gland, bone marrow, brain, placenta, prostate, salivary gland, skeletal muscle, testis, thymus, thyroid gland, heart, spinal cord, fetal brain and fetal liver.1 Publication

Gene expression databases

BgeeiQ9H8S9.
CleanExiHS_MOBKL1B.
GenevestigatoriQ9H8S9.

Organism-specific databases

HPAiHPA047088.

Interactioni

Subunit structurei

Binds STK38 and STK38L. Interacts with LATS1 and LATS2. Forms a tripartite complex with STK38 and STK3/MST2.3 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
Q9WMX22EBI-748229,EBI-6863748From a different organism.
LATS1O958359EBI-748229,EBI-444209
LATS2Q9NRM74EBI-748229,EBI-3506895
STK38Q152082EBI-748229,EBI-458376
STK38LQ9Y2H13EBI-748229,EBI-991501

Protein-protein interaction databases

BioGridi120527. 52 interactions.
DIPiDIP-36594N.
IntActiQ9H8S9. 39 interactions.
MINTiMINT-197366.
STRINGi9606.ENSP00000379364.

Structurei

Secondary structure

1
216
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Turni42 – 454Combined sources
Helixi53 – 7523Combined sources
Helixi76 – 783Combined sources
Turni81 – 833Combined sources
Beta strandi88 – 903Combined sources
Beta strandi93 – 953Combined sources
Beta strandi100 – 1023Combined sources
Helixi111 – 12616Combined sources
Turni129 – 1313Combined sources
Beta strandi135 – 1373Combined sources
Helixi144 – 16522Combined sources
Helixi167 – 1726Combined sources
Helixi176 – 19318Combined sources
Helixi198 – 2014Combined sources
Helixi202 – 2043Combined sources
Helixi205 – 2117Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1PI1X-ray2.00A33-216[»]
4J1VX-ray1.95A/C33-216[»]
4JIZX-ray2.10A40-211[»]
ProteinModelPortaliQ9H8S9.
SMRiQ9H8S9. Positions 33-216.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiQ9H8S9.

Family & Domainsi

Sequence similaritiesi

Belongs to the MOB1/phocein family.Curated

Phylogenomic databases

eggNOGiNOG287143.
GeneTreeiENSGT00550000074456.
HOGENOMiHOG000164685.
HOVERGENiHBG052489.
InParanoidiQ9H8S9.
KOiK06685.
OMAiEFCTETS.
OrthoDBiEOG7N0C5K.
PhylomeDBiQ9H8S9.
TreeFamiTF300789.

Family and domain databases

Gene3Di1.20.140.30. 1 hit.
InterProiIPR005301. Mob1_phocein.
[Graphical view]
PANTHERiPTHR22599. PTHR22599. 1 hit.
PfamiPF03637. Mob1_phocein. 1 hit.
[Graphical view]
SUPFAMiSSF101152. SSF101152. 1 hit.

Sequences (2)i

Sequence statusi: Complete.

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

This entry describes 2 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform 1 (identifier: Q9H8S9-1) [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
MSFLFSSRSS KTFKPKKNIP EGSHQYELLK HAEATLGSGN LRQAVMLPEG
60 70 80 90 100
EDLNEWIAVN TVDFFNQINM LYGTITEFCT EASCPVMSAG PRYEYHWADG
110 120 130 140 150
TNIKKPIKCS APKYIDYLMT WVQDQLDDET LFPSKIGVPF PKNFMSVAKT
160 170 180 190 200
ILKRLFRVYA HIYHQHFDSV MQLQEEAHLN TSFKHFIFFV QEFNLIDRRE
210
LAPLQELIEK LGSKDR
Length:216
Mass (Da):25,080
Last modified:January 23, 2007 - v4
Checksum:i58043AECAD1F5987
GO
Isoform 2 (identifier: Q9H8S9-2) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     138-148: VPFPKNFMSVA → ELTLSKYSFFF
     149-216: Missing.

Note: May be due to an intron retention.

Show »
Length:148
Mass (Da):16,928
Checksum:i70F00C42359120F2
GO

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti5 – 51F → L in BAB14525 (PubMed:14702039).Curated
Sequence conflicti176 – 1761E → G in BAA91810 (PubMed:14702039).Curated

Alternative sequence

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Alternative sequencei138 – 14811VPFPKNFMSVA → ELTLSKYSFFF in isoform 2. 1 PublicationVSP_012295Add
BLAST
Alternative sequencei149 – 21668Missing in isoform 2. 1 PublicationVSP_012296Add
BLAST

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AB016839 mRNA. Translation: BAB19058.1.
AJ577474 mRNA. Translation: CAE12093.1.
AK001650 mRNA. Translation: BAA91810.1.
AK021657 mRNA. Translation: BAB13868.1.
AK023321 mRNA. Translation: BAB14525.1.
AC073263 Genomic DNA. Translation: AAX93060.1.
BC003398 mRNA. Translation: AAH03398.1.
CCDSiCCDS46340.1. [Q9H8S9-1]
RefSeqiNP_060691.2. NM_018221.3. [Q9H8S9-1]
UniGeneiHs.602092.

Genome annotation databases

EnsembliENST00000396049; ENSP00000379364; ENSG00000114978. [Q9H8S9-1]
GeneIDi55233.
KEGGihsa:55233.
UCSCiuc002skh.4. human. [Q9H8S9-1]
uc002ski.2. human. [Q9H8S9-2]

Polymorphism databases

DMDMi56749356.

Keywords - Coding sequence diversityi

Alternative splicing

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AB016839 mRNA. Translation: BAB19058.1.
AJ577474 mRNA. Translation: CAE12093.1.
AK001650 mRNA. Translation: BAA91810.1.
AK021657 mRNA. Translation: BAB13868.1.
AK023321 mRNA. Translation: BAB14525.1.
AC073263 Genomic DNA. Translation: AAX93060.1.
BC003398 mRNA. Translation: AAH03398.1.
CCDSiCCDS46340.1. [Q9H8S9-1]
RefSeqiNP_060691.2. NM_018221.3. [Q9H8S9-1]
UniGeneiHs.602092.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1PI1X-ray2.00A33-216[»]
4J1VX-ray1.95A/C33-216[»]
4JIZX-ray2.10A40-211[»]
ProteinModelPortaliQ9H8S9.
SMRiQ9H8S9. Positions 33-216.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi120527. 52 interactions.
DIPiDIP-36594N.
IntActiQ9H8S9. 39 interactions.
MINTiMINT-197366.
STRINGi9606.ENSP00000379364.

PTM databases

PhosphoSiteiQ9H8S9.

Polymorphism databases

DMDMi56749356.

2D gel databases

OGPiQ9H8S9.

Proteomic databases

MaxQBiQ9H8S9.
PaxDbiQ9H8S9.
PRIDEiQ9H8S9.

Protocols and materials databases

DNASUi55233.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000396049; ENSP00000379364; ENSG00000114978. [Q9H8S9-1]
GeneIDi55233.
KEGGihsa:55233.
UCSCiuc002skh.4. human. [Q9H8S9-1]
uc002ski.2. human. [Q9H8S9-2]

Organism-specific databases

CTDi55233.
GeneCardsiGC02M074382.
HGNCiHGNC:16015. MOB1A.
HPAiHPA047088.
MIMi609281. gene.
neXtProtiNX_Q9H8S9.
PharmGKBiPA25894.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiNOG287143.
GeneTreeiENSGT00550000074456.
HOGENOMiHOG000164685.
HOVERGENiHBG052489.
InParanoidiQ9H8S9.
KOiK06685.
OMAiEFCTETS.
OrthoDBiEOG7N0C5K.
PhylomeDBiQ9H8S9.
TreeFamiTF300789.

Enzyme and pathway databases

ReactomeiREACT_118607. Signaling by Hippo.

Miscellaneous databases

EvolutionaryTraceiQ9H8S9.
GeneWikiiMOBKL1B.
GenomeRNAii55233.
NextBioi59245.
PROiQ9H8S9.
SOURCEiSearch...

Gene expression databases

BgeeiQ9H8S9.
CleanExiHS_MOBKL1B.
GenevestigatoriQ9H8S9.

Family and domain databases

Gene3Di1.20.140.30. 1 hit.
InterProiIPR005301. Mob1_phocein.
[Graphical view]
PANTHERiPTHR22599. PTHR22599. 1 hit.
PfamiPF03637. Mob1_phocein. 1 hit.
[Graphical view]
SUPFAMiSSF101152. SSF101152. 1 hit.
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "Human MOB1."
    Kagaya S., Kotani S., Todokoro K.
    Submitted (AUG-1998) to the EMBL/GenBank/DDBJ databases
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
  2. "Characterization of the human Mob-1 like proteins."
    Florindo C.S., Tavares A.A.
    Submitted (JUL-2003) to the EMBL/GenBank/DDBJ databases
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
  3. "Complete sequencing and characterization of 21,243 full-length human cDNAs."
    Ota T., Suzuki Y., Nishikawa T., Otsuki T., Sugiyama T., Irie R., Wakamatsu A., Hayashi K., Sato H., Nagai K., Kimura K., Makita H., Sekine M., Obayashi M., Nishi T., Shibahara T., Tanaka T., Ishii S.
    , Yamamoto J., Saito K., Kawai Y., Isono Y., Nakamura Y., Nagahari K., Murakami K., Yasuda T., Iwayanagi T., Wagatsuma M., Shiratori A., Sudo H., Hosoiri T., Kaku Y., Kodaira H., Kondo H., Sugawara M., Takahashi M., Kanda K., Yokoi T., Furuya T., Kikkawa E., Omura Y., Abe K., Kamihara K., Katsuta N., Sato K., Tanikawa M., Yamazaki M., Ninomiya K., Ishibashi T., Yamashita H., Murakawa K., Fujimori K., Tanai H., Kimata M., Watanabe M., Hiraoka S., Chiba Y., Ishida S., Ono Y., Takiguchi S., Watanabe S., Yosida M., Hotuta T., Kusano J., Kanehori K., Takahashi-Fujii A., Hara H., Tanase T.-O., Nomura Y., Togiya S., Komai F., Hara R., Takeuchi K., Arita M., Imose N., Musashino K., Yuuki H., Oshima A., Sasaki N., Aotsuka S., Yoshikawa Y., Matsunawa H., Ichihara T., Shiohata N., Sano S., Moriya S., Momiyama H., Satoh N., Takami S., Terashima Y., Suzuki O., Nakagawa S., Senoh A., Mizoguchi H., Goto Y., Shimizu F., Wakebe H., Hishigaki H., Watanabe T., Sugiyama A., Takemoto M., Kawakami B., Yamazaki M., Watanabe K., Kumagai A., Itakura S., Fukuzumi Y., Fujimori Y., Komiyama M., Tashiro H., Tanigami A., Fujiwara T., Ono T., Yamada K., Fujii Y., Ozaki K., Hirao M., Ohmori Y., Kawabata A., Hikiji T., Kobatake N., Inagaki H., Ikema Y., Okamoto S., Okitani R., Kawakami T., Noguchi S., Itoh T., Shigeta K., Senba T., Matsumura K., Nakajima Y., Mizuno T., Morinaga M., Sasaki M., Togashi T., Oyama M., Hata H., Watanabe M., Komatsu T., Mizushima-Sugano J., Satoh T., Shirai Y., Takahashi Y., Nakagawa K., Okumura K., Nagase T., Nomura N., Kikuchi H., Masuho Y., Yamashita R., Nakai K., Yada T., Nakamura Y., Ohara O., Isogai T., Sugano S.
    Nat. Genet. 36:40-45(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORMS 1 AND 2).
    Tissue: Embryo and Ovary.
  4. "Generation and annotation of the DNA sequences of human chromosomes 2 and 4."
    Hillier L.W., Graves T.A., Fulton R.S., Fulton L.A., Pepin K.H., Minx P., Wagner-McPherson C., Layman D., Wylie K., Sekhon M., Becker M.C., Fewell G.A., Delehaunty K.D., Miner T.L., Nash W.E., Kremitzki C., Oddy L., Du H.
    , Sun H., Bradshaw-Cordum H., Ali J., Carter J., Cordes M., Harris A., Isak A., van Brunt A., Nguyen C., Du F., Courtney L., Kalicki J., Ozersky P., Abbott S., Armstrong J., Belter E.A., Caruso L., Cedroni M., Cotton M., Davidson T., Desai A., Elliott G., Erb T., Fronick C., Gaige T., Haakenson W., Haglund K., Holmes A., Harkins R., Kim K., Kruchowski S.S., Strong C.M., Grewal N., Goyea E., Hou S., Levy A., Martinka S., Mead K., McLellan M.D., Meyer R., Randall-Maher J., Tomlinson C., Dauphin-Kohlberg S., Kozlowicz-Reilly A., Shah N., Swearengen-Shahid S., Snider J., Strong J.T., Thompson J., Yoakum M., Leonard S., Pearman C., Trani L., Radionenko M., Waligorski J.E., Wang C., Rock S.M., Tin-Wollam A.-M., Maupin R., Latreille P., Wendl M.C., Yang S.-P., Pohl C., Wallis J.W., Spieth J., Bieri T.A., Berkowicz N., Nelson J.O., Osborne J., Ding L., Meyer R., Sabo A., Shotland Y., Sinha P., Wohldmann P.E., Cook L.L., Hickenbotham M.T., Eldred J., Williams D., Jones T.A., She X., Ciccarelli F.D., Izaurralde E., Taylor J., Schmutz J., Myers R.M., Cox D.R., Huang X., McPherson J.D., Mardis E.R., Clifton S.W., Warren W.C., Chinwalla A.T., Eddy S.R., Marra M.A., Ovcharenko I., Furey T.S., Miller W., Eichler E.E., Bork P., Suyama M., Torrents D., Waterston R.H., Wilson R.K.
    Nature 434:724-731(2005) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
  5. "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
    The MGC Project Team
    Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1).
    Tissue: Placenta.
  6. "Exploring proteomes and analyzing protein processing by mass spectrometric identification of sorted N-terminal peptides."
    Gevaert K., Goethals M., Martens L., Van Damme J., Staes A., Thomas G.R., Vandekerckhove J.
    Nat. Biotechnol. 21:566-569(2003) [PubMed] [Europe PMC] [Abstract]
    Cited for: PROTEIN SEQUENCE OF 2-8, ACETYLATION AT SER-2.
    Tissue: Platelet.
  7. "Mechanism of activation of NDR (nuclear Dbf2-related) protein kinase by the hMOB1 protein."
    Bichsel S.J., Tamaskovic R., Stegert M.R., Hemmings B.A.
    J. Biol. Chem. 279:35228-35235(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, PHOSPHORYLATION, INTERACTION WITH STK38 AND STK38L.
  8. "MOBKL1A/MOBKL1B phosphorylation by MST1 and MST2 inhibits cell proliferation."
    Praskova M., Xia F., Avruch J.
    Curr. Biol. 18:311-321(2008) [PubMed] [Europe PMC] [Abstract]
    Cited for: PHOSPHORYLATION AT THR-12 AND THR-35 BY STK3/MST2 AND STK4/MST1.
  9. "Threonine 74 of MOB1 is a putative key phosphorylation site by MST2 to form the scaffold to activate nuclear Dbf2-related kinase 1."
    Hirabayashi S., Nakagawa K., Sumita K., Hidaka S., Kawai T., Ikeda M., Kawata A., Ohno K., Hata Y.
    Oncogene 27:4281-4292(2008) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, PHOSPHORYLATION AT THR-74 AND THR-181, INTERACTION WITH STK38 AND STK3/MST2.
  10. "Molecular characterization of human homologs of yeast MOB1."
    Chow A., Hao Y., Yang X.
    Int. J. Cancer 126:2079-2089(2010) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION, INTERACTION WITH LATS1 AND LATS2, TISSUE SPECIFICITY.
  11. Cited for: ACETYLATION [LARGE SCALE ANALYSIS] AT SER-2, IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS], CLEAVAGE OF INITIATOR METHIONINE [LARGE SCALE ANALYSIS].
  12. "Crystal structure of a human Mob1 protein: toward understanding Mob-regulated cell cycle pathways."
    Stavridi E.S., Harris K.G., Huyen Y., Bothos J., Verwoerd P.-M., Stayrook S.E., Pavletich N.P., Jeffrey P.D., Luca F.C.
    Structure 11:1163-1170(2003) [PubMed] [Europe PMC] [Abstract]
    Cited for: X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) OF 33-216, PARTIAL PROTEIN SEQUENCE, IDENTIFICATION BY MASS SPECTROMETRY, ZINC-BINDING.

Entry informationi

Entry nameiMOB1A_HUMAN
AccessioniPrimary (citable) accession number: Q9H8S9
Secondary accession number(s): Q53S34
, Q9H3T5, Q9HAI0, Q9NVE2
Entry historyi
Integrated into UniProtKB/Swiss-Prot: December 21, 2004
Last sequence update: January 23, 2007
Last modified: March 4, 2015
This is version 123 of the entry and version 4 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, Direct protein sequencing, Reference proteome

Documents

  1. Human chromosome 2
    Human chromosome 2: entries, gene names and cross-references to MIM
  2. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  3. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  4. 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.