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Protein

Negative elongation factor C/D

Gene

NELFCD

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

Functioni

Essential component of the NELF complex, a complex that negatively regulates the elongation of transcription by RNA polymerase II. The NELF complex, which acts via an association with the DSIF complex and causes transcriptional pausing, is counteracted by the P-TEFb kinase complex.2 Publications

GO - Biological processi

Complete GO annotation...

Keywords - Molecular functioni

Repressor

Keywords - Biological processi

Transcription, Transcription regulation

Enzyme and pathway databases

ReactomeiR-HSA-112382. Formation of RNA Pol II elongation complex.
R-HSA-113418. Formation of the Early Elongation Complex.
R-HSA-167152. Formation of HIV elongation complex in the absence of HIV Tat.
R-HSA-167158. Formation of the HIV-1 Early Elongation Complex.
R-HSA-167200. Formation of HIV-1 elongation complex containing HIV-1 Tat.
R-HSA-167238. Pausing and recovery of Tat-mediated HIV elongation.
R-HSA-167242. Abortive elongation of HIV-1 transcript in the absence of Tat.
R-HSA-167243. Tat-mediated HIV elongation arrest and recovery.
R-HSA-167246. Tat-mediated elongation of the HIV-1 transcript.
R-HSA-167287. HIV elongation arrest and recovery.
R-HSA-167290. Pausing and recovery of HIV elongation.
R-HSA-674695. RNA Polymerase II Pre-transcription Events.
R-HSA-6796648. TP53 Regulates Transcription of DNA Repair Genes.
R-HSA-75955. RNA Polymerase II Transcription Elongation.

Names & Taxonomyi

Protein namesi
Recommended name:
Negative elongation factor C/D
Short name:
NELF-C/D
Alternative name(s):
TH1-like protein
Gene namesi
Name:NELFCD
Synonyms:NELFD, TH1, TH1L
ORF Names:HSPC130
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 20

Organism-specific databases

HGNCiHGNC:15934. NELFCD.

Subcellular locationi

GO - Cellular componenti

  • membrane Source: UniProtKB
  • NELF complex Source: UniProtKB
  • nucleoplasm Source: Reactome
Complete GO annotation...

Keywords - Cellular componenti

Nucleus

Pathology & Biotechi

Organism-specific databases

PharmGKBiPA38055.

Polymorphism and mutation databases

DMDMi38372376.

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 590590Negative elongation factor C/DPRO_0000019456Add
BLAST

Proteomic databases

EPDiQ8IXH7.
MaxQBiQ8IXH7.
PaxDbiQ8IXH7.
PeptideAtlasiQ8IXH7.
PRIDEiQ8IXH7.

PTM databases

iPTMnetiQ8IXH7.
PhosphoSiteiQ8IXH7.

Expressioni

Tissue specificityi

Widely expressed. Expressed in heart, brain, lung, placenta, liver, skeletal and cardiac muscle, adrenal, thyroid, kidney and pancreas.2 Publications

Gene expression databases

BgeeiQ8IXH7.
ExpressionAtlasiQ8IXH7. baseline and differential.
GenevisibleiQ8IXH7. HS.

Interactioni

Subunit structurei

The NELF complex is composed of NELFA, NELFB, NELFCD (isoform NELF-C or isoform NELF-D) and NELFE. Interacts with ARAF1.2 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
ARAFP103985EBI-536725,EBI-365961
NELFAQ9H3P24EBI-6109710,EBI-5461341

Protein-protein interaction databases

BioGridi119572. 44 interactions.
DIPiDIP-34061N.
IntActiQ8IXH7. 28 interactions.
MINTiMINT-260753.
STRINGi9606.ENSP00000342300.

Structurei

3D structure databases

ProteinModelPortaliQ8IXH7.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Belongs to the NELF-D family.Curated

Phylogenomic databases

eggNOGiENOG410IFGF. Eukaryota.
ENOG410XSDJ. LUCA.
HOVERGENiHBG052597.
InParanoidiQ8IXH7.
KOiK15181.
OrthoDBiEOG708VZ9.
PhylomeDBiQ8IXH7.
TreeFamiTF324118.

Family and domain databases

InterProiIPR006942. TH1.
[Graphical view]
PANTHERiPTHR12144. PTHR12144. 1 hit.
PfamiPF04858. TH1. 1 hit.
[Graphical view]

Sequences (3)i

Sequence statusi: Complete.

This entry describes 3 isoformsi produced by alternative splicing and alternative initiation. AlignAdd to basket

Isoform NELF-C (identifier: Q8IXH7-1) [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
MAGAVPGAIM DEDYYGSAAE WGDEADGGQQ EDDSGEGEDD AEVQQECLHK
60 70 80 90 100
FSTRDYIMEP SIFNTLKRYF QAGGSPENVI QLLSENYTAV AQTVNLLAEW
110 120 130 140 150
LIQTGVEPVQ VQETVENHLK SLLIKHFDPR KADSIFTEEG ETPAWLEQMI
160 170 180 190 200
AHTTWRDLFY KLAEAHPDCL MLNFTVKLIS DAGYQGEITS VSTACQQLEV
210 220 230 240 250
FSRVLRTSLA TILDGGEENL EKNLPEFAKM VCHGEHTYLF AQAMMSVLAQ
260 270 280 290 300
EEQGGSAVRR IAQEVQRFAQ EKGHDASQIT LALGTAASYP RACQALGAML
310 320 330 340 350
SKGALNPADI TVLFKMFTSM DPPPVELIRV PAFLDLFMQS LFKPGARINQ
360 370 380 390 400
DHKHKYIHIL AYAASVVETW KKNKRVSINK DELKSTSKAV ETVHNLCCNE
410 420 430 440 450
NKGASELVAE LSTLYQCIRF PVVAMGVLKW VDWTVSEPRY FQLQTDHTPV
460 470 480 490 500
HLALLDEIST CHQLLHPQVL QLLVKLFETE HSQLDVMEQL ELKKTLLDRM
510 520 530 540 550
VHLLSRGYVL PVVSYIRKCL EKLDTDISLI RYFVTEVLDV IAPPYTSDFV
560 570 580 590
QLFLPILEND SIAGTIKTEG EHDPVTEFIA HCKSNFIMVN
Length:590
Mass (Da):66,247
Last modified:November 14, 2003 - v2
Checksum:i425437DC46DAF953
GO
Isoform 3 (identifier: Q8IXH7-3) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     178-201: LISDAGYQGEITSVSTACQQLEVF → VGRVLELRRKVFMNVYFWLLVCFL
     202-590: Missing.

Note: No experimental confirmation available.
Show »
Length:201
Mass (Da):22,903
Checksum:i28EA9E5A52CD68FF
GO
Isoform NELF-D (identifier: Q8IXH7-4) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     1-9: Missing.

Note: Produced by alternative initiation at Met-10 of isoform NELF-C.
Show »
Length:581
Mass (Da):65,479
Checksum:iDD20EFAF08DE67E8
GO

Sequence cautioni

The sequence AAF29094.1 differs from that shown. Reason: Frameshift at positions 462 and 464. Curated
The sequence BAA91618.1 differs from that shown. Reason: Erroneous initiation. Curated
The sequence BAB14519.1 differs from that shown. Reason: Erroneous initiation. Curated
The sequence CAB64339.1 differs from that shown. Reason: Erroneous initiation. Curated

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti117 – 1171N → D in BAA91618 (PubMed:14702039).Curated
Sequence conflicti306 – 3061N → S in BAB14729 (PubMed:14702039).Curated
Sequence conflicti430 – 4301W → R in BAA91618 (PubMed:14702039).Curated
Sequence conflicti497 – 4971L → P in BAA91618 (PubMed:14702039).Curated
Sequence conflicti573 – 5731D → V in BAA91618 (PubMed:14702039).Curated

Alternative sequence

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Alternative sequencei1 – 99Missing in isoform NELF-D. CuratedVSP_018769
Alternative sequencei178 – 20124LISDA…QLEVF → VGRVLELRRKVFMNVYFWLL VCFL in isoform 3. 1 PublicationVSP_008950Add
BLAST
Alternative sequencei202 – 590389Missing in isoform 3. 1 PublicationVSP_008951Add
BLAST

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AJ238374 mRNA. Translation: CAB64337.1.
AJ238375 mRNA. Translation: CAB64373.1.
AJ238379 mRNA. Translation: CAB64339.1. Different initiation.
AF161479 mRNA. Translation: AAF29094.1. Frameshift.
AK001316 mRNA. Translation: BAA91618.1. Different initiation.
AK023310 mRNA. Translation: BAB14519.1. Different initiation.
AK023927 mRNA. Translation: BAB14729.1.
AK293410 mRNA. Translation: BAG56917.1.
AL109840 Genomic DNA. Translation: CAC09368.1.
BC014952 mRNA. Translation: AAH14952.1.
RefSeqiNP_945327.2. NM_198976.2.
UniGeneiHs.517148.

Genome annotation databases

EnsembliENST00000344018; ENSP00000342300; ENSG00000101158.
GeneIDi51497.
KEGGihsa:51497.
UCSCiuc061ydt.1. human. [Q8IXH7-1]

Keywords - Coding sequence diversityi

Alternative initiation, Alternative splicing

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AJ238374 mRNA. Translation: CAB64337.1.
AJ238375 mRNA. Translation: CAB64373.1.
AJ238379 mRNA. Translation: CAB64339.1. Different initiation.
AF161479 mRNA. Translation: AAF29094.1. Frameshift.
AK001316 mRNA. Translation: BAA91618.1. Different initiation.
AK023310 mRNA. Translation: BAB14519.1. Different initiation.
AK023927 mRNA. Translation: BAB14729.1.
AK293410 mRNA. Translation: BAG56917.1.
AL109840 Genomic DNA. Translation: CAC09368.1.
BC014952 mRNA. Translation: AAH14952.1.
RefSeqiNP_945327.2. NM_198976.2.
UniGeneiHs.517148.

3D structure databases

ProteinModelPortaliQ8IXH7.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi119572. 44 interactions.
DIPiDIP-34061N.
IntActiQ8IXH7. 28 interactions.
MINTiMINT-260753.
STRINGi9606.ENSP00000342300.

PTM databases

iPTMnetiQ8IXH7.
PhosphoSiteiQ8IXH7.

Polymorphism and mutation databases

DMDMi38372376.

Proteomic databases

EPDiQ8IXH7.
MaxQBiQ8IXH7.
PaxDbiQ8IXH7.
PeptideAtlasiQ8IXH7.
PRIDEiQ8IXH7.

Protocols and materials databases

DNASUi51497.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000344018; ENSP00000342300; ENSG00000101158.
GeneIDi51497.
KEGGihsa:51497.
UCSCiuc061ydt.1. human. [Q8IXH7-1]

Organism-specific databases

CTDi51497.
GeneCardsiNELFCD.
H-InvDBHIX0138057.
HGNCiHGNC:15934. NELFCD.
MIMi605297. gene.
neXtProtiNX_Q8IXH7.
PharmGKBiPA38055.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiENOG410IFGF. Eukaryota.
ENOG410XSDJ. LUCA.
HOVERGENiHBG052597.
InParanoidiQ8IXH7.
KOiK15181.
OrthoDBiEOG708VZ9.
PhylomeDBiQ8IXH7.
TreeFamiTF324118.

Enzyme and pathway databases

ReactomeiR-HSA-112382. Formation of RNA Pol II elongation complex.
R-HSA-113418. Formation of the Early Elongation Complex.
R-HSA-167152. Formation of HIV elongation complex in the absence of HIV Tat.
R-HSA-167158. Formation of the HIV-1 Early Elongation Complex.
R-HSA-167200. Formation of HIV-1 elongation complex containing HIV-1 Tat.
R-HSA-167238. Pausing and recovery of Tat-mediated HIV elongation.
R-HSA-167242. Abortive elongation of HIV-1 transcript in the absence of Tat.
R-HSA-167243. Tat-mediated HIV elongation arrest and recovery.
R-HSA-167246. Tat-mediated elongation of the HIV-1 transcript.
R-HSA-167287. HIV elongation arrest and recovery.
R-HSA-167290. Pausing and recovery of HIV elongation.
R-HSA-674695. RNA Polymerase II Pre-transcription Events.
R-HSA-6796648. TP53 Regulates Transcription of DNA Repair Genes.
R-HSA-75955. RNA Polymerase II Transcription Elongation.

Miscellaneous databases

GeneWikiiTH1L.
GenomeRNAii51497.
PROiQ8IXH7.
SOURCEiSearch...

Gene expression databases

BgeeiQ8IXH7.
ExpressionAtlasiQ8IXH7. baseline and differential.
GenevisibleiQ8IXH7. HS.

Family and domain databases

InterProiIPR006942. TH1.
[Graphical view]
PANTHERiPTHR12144. PTHR12144. 1 hit.
PfamiPF04858. TH1. 1 hit.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "Characterization of TH1 and CTSZ, two non-imprinted genes downstream of GNAS1 in chromosome 20q13."
    Bonthron D.T., Hayward B.E., Moran V., Strain L.
    Hum. Genet. 107:165-175(2000) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE (ISOFORM NELF-C), TISSUE SPECIFICITY.
  2. "Cloning and functional analysis of cDNAs with open reading frames for 300 previously undefined genes expressed in CD34+ hematopoietic stem/progenitor cells."
    Zhang Q.-H., Ye M., Wu X.-Y., Ren S.-X., Zhao M., Zhao C.-J., Fu G., Shen Y., Fan H.-Y., Lu G., Zhong M., Xu X.-R., Han Z.-G., Zhang J.-W., Tao J., Huang Q.-H., Zhou J., Hu G.-X.
    , Gu J., Chen S.-J., Chen Z.
    Genome Res. 10:1546-1560(2000) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM NELF-C).
    Tissue: Umbilical cord blood.
  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 NELF-C AND 3).
    Tissue: Ovarian carcinoma, Teratocarcinoma and Thyroid.
  4. "The DNA sequence and comparative analysis of human chromosome 20."
    Deloukas P., Matthews L.H., Ashurst J.L., Burton J., Gilbert J.G.R., Jones M., Stavrides G., Almeida J.P., Babbage A.K., Bagguley C.L., Bailey J., Barlow K.F., Bates K.N., Beard L.M., Beare D.M., Beasley O.P., Bird C.P., Blakey S.E.
    , Bridgeman A.M., Brown A.J., Buck D., Burrill W.D., Butler A.P., Carder C., Carter N.P., Chapman J.C., Clamp M., Clark G., Clark L.N., Clark S.Y., Clee C.M., Clegg S., Cobley V.E., Collier R.E., Connor R.E., Corby N.R., Coulson A., Coville G.J., Deadman R., Dhami P.D., Dunn M., Ellington A.G., Frankland J.A., Fraser A., French L., Garner P., Grafham D.V., Griffiths C., Griffiths M.N.D., Gwilliam R., Hall R.E., Hammond S., Harley J.L., Heath P.D., Ho S., Holden J.L., Howden P.J., Huckle E., Hunt A.R., Hunt S.E., Jekosch K., Johnson C.M., Johnson D., Kay M.P., Kimberley A.M., King A., Knights A., Laird G.K., Lawlor S., Lehvaeslaiho M.H., Leversha M.A., Lloyd C., Lloyd D.M., Lovell J.D., Marsh V.L., Martin S.L., McConnachie L.J., McLay K., McMurray A.A., Milne S.A., Mistry D., Moore M.J.F., Mullikin J.C., Nickerson T., Oliver K., Parker A., Patel R., Pearce T.A.V., Peck A.I., Phillimore B.J.C.T., Prathalingam S.R., Plumb R.W., Ramsay H., Rice C.M., Ross M.T., Scott C.E., Sehra H.K., Shownkeen R., Sims S., Skuce C.D., Smith M.L., Soderlund C., Steward C.A., Sulston J.E., Swann R.M., Sycamore N., Taylor R., Tee L., Thomas D.W., Thorpe A., Tracey A., Tromans A.C., Vaudin M., Wall M., Wallis J.M., Whitehead S.L., Whittaker P., Willey D.L., Williams L., Williams S.A., Wilming L., Wray P.W., Hubbard T., Durbin R.M., Bentley D.R., Beck S., Rogers J.
    Nature 414:865-871(2001) [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 NELF-C).
    Tissue: Skin.
  6. "Human transcription elongation factor NELF: identification of novel subunits and reconstitution of the functionally active complex."
    Narita T., Yamaguchi Y., Yano K., Sugimoto S., Chanarat S., Wada T., Kim D.-K., Hasegawa J., Omori M., Inukai N., Endoh M., Yamada T., Handa H.
    Mol. Cell. Biol. 23:1863-1873(2003) [PubMed] [Europe PMC] [Abstract]
    Cited for: PROTEIN SEQUENCE OF 126-139; 223-230; 303-315 AND 476-491, IDENTIFICATION IN A NELF COMPLEX, ALTERNATIVE INITIATION, FUNCTION, TISSUE SPECIFICITY.
  7. "Identification of TH1 as an interaction partner of A-Raf kinase."
    Yin X.L., Chen S., Gu J.X.
    Mol. Cell. Biochem. 231:69-74(2002) [PubMed] [Europe PMC] [Abstract]
    Cited for: INTERACTION WITH ARAF1.
  8. "NELF, a multisubunit complex containing RD, cooperates with DSIF to repress RNA polymerase II elongation."
    Yamaguchi Y., Takagi T., Wada T., Yano K., Furuya A., Sugimoto S., Hasegawa J., Handa H.
    Cell 97:41-51(1999) [PubMed] [Europe PMC] [Abstract]
    Cited for: FUNCTION OF THE NELF COMPLEX.
  9. Cited for: IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].

Entry informationi

Entry nameiNELFD_HUMAN
AccessioniPrimary (citable) accession number: Q8IXH7
Secondary accession number(s): B4DE06
, Q9BYL2, Q9H405, Q9H888, Q9H8T3, Q9NVX5, Q9P029, Q9UGN1, Q9UGN2, Q9UGN3
Entry historyi
Integrated into UniProtKB/Swiss-Prot: November 14, 2003
Last sequence update: November 14, 2003
Last modified: July 6, 2016
This is version 137 of the entry and version 2 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

Complete proteome, Direct protein sequencing, Reference proteome

Documents

  1. Human chromosome 20
    Human chromosome 20: 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. 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.