Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Cathepsin F

Gene

CTSF

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

Functioni

Thiol protease which is believed to participate in intracellular degradation and turnover of proteins. Has also been implicated in tumor invasion and metastasis.

Catalytic activityi

The recombinant enzyme cleaves synthetic substrates with Phe and Leu (better than Val) in P2, with high specificity constant (k(cat)/K(m)) comparable to that of cathepsin L.

Sites

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Active sitei295 – 29511 Publication
Active sitei431 – 43111 Publication
Active sitei451 – 4511By similarity

GO - Molecular functioni

  1. cysteine-type endopeptidase activity Source: ProtInc

GO - Biological processi

  1. antigen processing and presentation of exogenous peptide antigen via MHC class II Source: Reactome
  2. proteolysis Source: ProtInc
Complete GO annotation...

Keywords - Molecular functioni

Hydrolase, Protease, Thiol protease

Enzyme and pathway databases

BRENDAi3.4.22.41. 2681.
ReactomeiREACT_121399. MHC class II antigen presentation.

Protein family/group databases

MEROPSiC01.018.

Names & Taxonomyi

Protein namesi
Recommended name:
Cathepsin F (EC:3.4.22.41)
Short name:
CATSF
Gene namesi
Name:CTSF
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
ProteomesiUP000005640 Componenti: Chromosome 11

Organism-specific databases

HGNCiHGNC:2531. CTSF.

Subcellular locationi

GO - Cellular componenti

  1. extracellular vesicular exosome Source: UniProtKB
  2. lysosomal lumen Source: Reactome
  3. lysosome Source: ProtInc
  4. vesicle Source: UniProtKB
Complete GO annotation...

Keywords - Cellular componenti

Lysosome

Pathology & Biotechi

Involvement in diseasei

Ceroid lipofuscinosis, neuronal, 13 (CLN13)1 Publication

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

Disease descriptionA form of neuronal ceroid lipofuscinosis characterized by adult onset of progressive cognitive decline and motor dysfunction leading to dementia and often early death. Some patients develop seizures. Neuronal ceroid lipofuscinoses are progressive neurodegenerative, lysosomal storage diseases characterized by intracellular accumulation of autofluorescent liposomal material.

See also OMIM:615362
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Natural varianti231 – 2311Y → C in CLN13. 1 Publication
VAR_070159
Natural varianti321 – 3211Q → R in CLN13. 1 Publication
VAR_070160
Natural varianti458 – 4581G → A in CLN13. 1 Publication
VAR_070161
Natural varianti480 – 4801S → L in CLN13. 1 Publication
VAR_070162

Keywords - Diseasei

Disease mutation, Neurodegeneration, Neuronal ceroid lipofuscinosis

Organism-specific databases

MIMi615362. phenotype.
Orphaneti352709. CLN13 disease.
PharmGKBiPA27031.

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Signal peptidei1 – 1919Sequence AnalysisAdd
BLAST
Propeptidei20 – 270251Activation peptidePRO_0000026202Add
BLAST
Chaini271 – 484214Cathepsin FPRO_0000026203Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Glycosylationi160 – 1601N-linked (GlcNAc...)Sequence Analysis
Glycosylationi195 – 1951N-linked (GlcNAc...)Sequence Analysis
Disulfide bondi292 ↔ 3331 Publication
Disulfide bondi326 ↔ 3661 Publication
Glycosylationi367 – 3671N-linked (GlcNAc...)1 Publication
Glycosylationi378 – 3781N-linked (GlcNAc...)1 Publication
Disulfide bondi424 ↔ 472By similarity
Glycosylationi440 – 4401N-linked (GlcNAc...)1 Publication

Keywords - PTMi

Disulfide bond, Glycoprotein, Zymogen

Proteomic databases

MaxQBiQ9UBX1.
PaxDbiQ9UBX1.
PeptideAtlasiQ9UBX1.
PRIDEiQ9UBX1.

PTM databases

PhosphoSiteiQ9UBX1.

Expressioni

Tissue specificityi

High expression levels in heart, skeletal muscle, brain, testis and ovary; moderate levels in prostate, placenta, liver and colon; and no detectable expression in peripheral leukocytes and thymus.

Gene expression databases

BgeeiQ9UBX1.
CleanExiHS_CTSF.
ExpressionAtlasiQ9UBX1. baseline and differential.
GenevestigatoriQ9UBX1.

Organism-specific databases

HPAiCAB002141.
HPA031431.
HPA055610.

Interactioni

Protein-protein interaction databases

BioGridi114261. 4 interactions.
STRINGi9606.ENSP00000310832.

Structurei

Secondary structure

1
484
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Helixi277 – 2804Combined sources
Beta strandi291 – 2933Combined sources
Helixi295 – 31218Combined sources
Helixi320 – 3267Combined sources
Beta strandi328 – 3303Combined sources
Helixi338 – 34811Combined sources
Turni354 – 3563Combined sources
Helixi370 – 3723Combined sources
Beta strandi378 – 3825Combined sources
Helixi387 – 39711Combined sources
Beta strandi400 – 4045Combined sources
Helixi407 – 4115Combined sources
Beta strandi414 – 4174Combined sources
Helixi421 – 4233Combined sources
Beta strandi431 – 44111Combined sources
Beta strandi444 – 4507Combined sources
Beta strandi462 – 4698Combined sources
Helixi471 – 4733Combined sources
Turni474 – 4774Combined sources
Beta strandi479 – 4824Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1D5Umodel-A271-484[»]
1M6DX-ray1.70A/B271-484[»]
ProteinModelPortaliQ9UBX1.
SMRiQ9UBX1. Positions 194-484.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiQ9UBX1.

Family & Domainsi

Sequence similaritiesi

Belongs to the peptidase C1 family.PROSITE-ProRule annotation

Keywords - Domaini

Signal

Phylogenomic databases

eggNOGiCOG4870.
GeneTreeiENSGT00760000118871.
HOGENOMiHOG000230774.
HOVERGENiHBG011513.
InParanoidiQ9UBX1.
KOiK01373.
OMAiNNMVRAQ.
OrthoDBiEOG7DJSKG.
PhylomeDBiQ9UBX1.
TreeFamiTF314550.

Family and domain databases

InterProiIPR000169. Pept_cys_AS.
IPR025660. Pept_his_AS.
IPR013128. Peptidase_C1A.
IPR000668. Peptidase_C1A_C.
IPR013201. Prot_inhib_I29.
[Graphical view]
PANTHERiPTHR12411. PTHR12411. 1 hit.
PfamiPF08246. Inhibitor_I29. 1 hit.
PF00112. Peptidase_C1. 1 hit.
[Graphical view]
PRINTSiPR00705. PAPAIN.
SMARTiSM00848. Inhibitor_I29. 1 hit.
SM00645. Pept_C1. 1 hit.
[Graphical view]
PROSITEiPS00139. THIOL_PROTEASE_CYS. 1 hit.
PS00639. THIOL_PROTEASE_HIS. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

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

Q9UBX1-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MAPWLQLLSL LGLLPGAVAA PAQPRAASFQ AWGPPSPELL APTRFALEMF
60 70 80 90 100
NRGRAAGTRA VLGLVRGRVR RAGQGSLYSL EATLEEPPCN DPMVCRLPVS
110 120 130 140 150
KKTLLCSFQV LDELGRHVLL RKDCGPVDTK VPGAGEPKSA FTQGSAMISS
160 170 180 190 200
LSQNHPDNRN ETFSSVISLL NEDPLSQDLP VKMASIFKNF VITYNRTYES
210 220 230 240 250
KEEARWRLSV FVNNMVRAQK IQALDRGTAQ YGVTKFSDLT EEEFRTIYLN
260 270 280 290 300
TLLRKEPGNK MKQAKSVGDL APPEWDWRSK GAVTKVKDQG MCGSCWAFSV
310 320 330 340 350
TGNVEGQWFL NQGTLLSLSE QELLDCDKMD KACMGGLPSN AYSAIKNLGG
360 370 380 390 400
LETEDDYSYQ GHMQSCNFSA EKAKVYINDS VELSQNEQKL AAWLAKRGPI
410 420 430 440 450
SVAINAFGMQ FYRHGISRPL RPLCSPWLID HAVLLVGYGN RSDVPFWAIK
460 470 480
NSWGTDWGEK GYYYLHRGSG ACGVNTMASS AVVD
Length:484
Mass (Da):53,366
Last modified:April 30, 2000 - v1
Checksum:i1D5D551B489D822B
GO

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti305 – 3051E → K in AAF13146 (Ref. 5) Curated
Sequence conflicti442 – 48443SDVPF…SAVVD → EFRCLSCIQPGHRQGWDHSI SGPLEGK (PubMed:17974005).CuratedAdd
BLAST

Natural variant

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Natural varianti153 – 1531Q → R.
Corresponds to variant rs11550508 [ dbSNP | Ensembl ].
VAR_051513
Natural varianti231 – 2311Y → C in CLN13. 1 Publication
VAR_070159
Natural varianti321 – 3211Q → R in CLN13. 1 Publication
VAR_070160
Natural varianti458 – 4581G → A in CLN13. 1 Publication
VAR_070161
Natural varianti480 – 4801S → L in CLN13. 1 Publication
VAR_070162

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AJ007331 mRNA. Translation: CAB42883.1.
AF088886 mRNA. Translation: AAD26616.2.
AF132894 Genomic DNA. Translation: AAD41790.1.
AF136279 mRNA. Translation: AAF13146.1.
AF071748 mRNA. Translation: AAC78838.1.
AF071749 mRNA. Translation: AAC78839.1.
AK313657 mRNA. Translation: BAG36411.1.
BC011682 mRNA. Translation: AAH11682.1.
BC036451 mRNA. Translation: AAH36451.1.
AL137742 mRNA. Translation: CAB70900.1.
CCDSiCCDS8144.1.
RefSeqiNP_003784.2. NM_003793.3.
UniGeneiHs.11590.

Genome annotation databases

EnsembliENST00000310325; ENSP00000310832; ENSG00000174080.
GeneIDi8722.
KEGGihsa:8722.
UCSCiuc001oip.3. human.

Polymorphism databases

DMDMi12643325.

Keywords - Coding sequence diversityi

Polymorphism

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AJ007331 mRNA. Translation: CAB42883.1.
AF088886 mRNA. Translation: AAD26616.2.
AF132894 Genomic DNA. Translation: AAD41790.1.
AF136279 mRNA. Translation: AAF13146.1.
AF071748 mRNA. Translation: AAC78838.1.
AF071749 mRNA. Translation: AAC78839.1.
AK313657 mRNA. Translation: BAG36411.1.
BC011682 mRNA. Translation: AAH11682.1.
BC036451 mRNA. Translation: AAH36451.1.
AL137742 mRNA. Translation: CAB70900.1.
CCDSiCCDS8144.1.
RefSeqiNP_003784.2. NM_003793.3.
UniGeneiHs.11590.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1D5Umodel-A271-484[»]
1M6DX-ray1.70A/B271-484[»]
ProteinModelPortaliQ9UBX1.
SMRiQ9UBX1. Positions 194-484.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi114261. 4 interactions.
STRINGi9606.ENSP00000310832.

Chemistry

BindingDBiQ9UBX1.
ChEMBLiCHEMBL2517.

Protein family/group databases

MEROPSiC01.018.

PTM databases

PhosphoSiteiQ9UBX1.

Polymorphism databases

DMDMi12643325.

Proteomic databases

MaxQBiQ9UBX1.
PaxDbiQ9UBX1.
PeptideAtlasiQ9UBX1.
PRIDEiQ9UBX1.

Protocols and materials databases

DNASUi8722.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000310325; ENSP00000310832; ENSG00000174080.
GeneIDi8722.
KEGGihsa:8722.
UCSCiuc001oip.3. human.

Organism-specific databases

CTDi8722.
GeneCardsiGC11M066332.
GeneReviewsiCTSF.
HGNCiHGNC:2531. CTSF.
HPAiCAB002141.
HPA031431.
HPA055610.
MIMi603539. gene.
615362. phenotype.
neXtProtiNX_Q9UBX1.
Orphaneti352709. CLN13 disease.
PharmGKBiPA27031.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiCOG4870.
GeneTreeiENSGT00760000118871.
HOGENOMiHOG000230774.
HOVERGENiHBG011513.
InParanoidiQ9UBX1.
KOiK01373.
OMAiNNMVRAQ.
OrthoDBiEOG7DJSKG.
PhylomeDBiQ9UBX1.
TreeFamiTF314550.

Enzyme and pathway databases

BRENDAi3.4.22.41. 2681.
ReactomeiREACT_121399. MHC class II antigen presentation.

Miscellaneous databases

ChiTaRSiCTSF. human.
EvolutionaryTraceiQ9UBX1.
GeneWikiiCathepsin_F.
GenomeRNAii8722.
NextBioi32715.
PROiQ9UBX1.
SOURCEiSearch...

Gene expression databases

BgeeiQ9UBX1.
CleanExiHS_CTSF.
ExpressionAtlasiQ9UBX1. baseline and differential.
GenevestigatoriQ9UBX1.

Family and domain databases

InterProiIPR000169. Pept_cys_AS.
IPR025660. Pept_his_AS.
IPR013128. Peptidase_C1A.
IPR000668. Peptidase_C1A_C.
IPR013201. Prot_inhib_I29.
[Graphical view]
PANTHERiPTHR12411. PTHR12411. 1 hit.
PfamiPF08246. Inhibitor_I29. 1 hit.
PF00112. Peptidase_C1. 1 hit.
[Graphical view]
PRINTSiPR00705. PAPAIN.
SMARTiSM00848. Inhibitor_I29. 1 hit.
SM00645. Pept_C1. 1 hit.
[Graphical view]
PROSITEiPS00139. THIOL_PROTEASE_CYS. 1 hit.
PS00639. THIOL_PROTEASE_HIS. 1 hit.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "Molecular cloning and structural and functional characterization of human cathepsin F, a new cysteine proteinase of the papain family with a long propeptide domain."
    Santamaria I., Velasco G., Pendas A.M., Paz A., Lopez-Otin C.
    J. Biol. Chem. 274:13800-13809(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA].
    Tissue: Prostate.
  2. "Full-length cDNA of human cathepsin F predicts the presence of a cystatin domain at the N-terminus of the cysteine protease zymogen."
    Naegler D.K., Sulea T., Menard R.
    Biochem. Biophys. Res. Commun. 257:313-318(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA].
    Tissue: Ovary.
  3. "The human cathepsin F gene -- a fusion product between an ancestral cathepsin and cystatin gene."
    Wex T., Wex H., Broemme D.
    Biol. Chem. 380:1439-1442(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
  4. "Human cathepsins F and W: a new subgroup of cathepsins."
    Wex T., Levy B., Wex H., Bromme D.
    Biochem. Biophys. Res. Commun. 259:401-407(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
  5. "Cathepsin F, a novel cysteine protease with an extremely long propeptide."
    Deussing J., Tisljar K., Papazoglou A., Peters C.
    Submitted (FEB-1999) to the EMBL/GenBank/DDBJ databases
    Cited for: NUCLEOTIDE SEQUENCE [MRNA].
    Tissue: Kidney.
  6. "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(2003) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
  7. "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(2003) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
    Tissue: Lung and Testis.
  8. "Human cathepsin F. Molecular cloning, functional expression, tissue localization, and enzymatic characterization."
    Wang B., Shi G.-P., Yao P.M., Li Z., Chapman H.A., Broemme D.
    J. Biol. Chem. 273:32000-32008(1997) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 147-484, CHARACTERIZATION.
    Tissue: Brain and Smooth muscle.
  9. Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] OF 161-484.
    Tissue: Testis.
  10. "Glycoproteomics analysis of human liver tissue by combination of multiple enzyme digestion and hydrazide chemistry."
    Chen R., Jiang X., Sun D., Han G., Wang F., Ye M., Wang L., Zou H.
    J. Proteome Res. 8:651-661(2008) [PubMed] [Europe PMC] [Abstract]
    Cited for: GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-367; ASN-378 AND ASN-440.
    Tissue: Liver.
  11. "The crystal structure of human cathepsin F and its implications for the development of novel immunomodulators."
    Somoza J.R., Palmer J.T., Ho J.D.
    J. Mol. Biol. 322:559-568(2001) [PubMed] [Europe PMC] [Abstract]
    Cited for: X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS) OF 271-484, ACTIVE SITE, DISULFIDE BONDS.
  12. Cited for: VARIANTS CLN13 CYS-231; ARG-321; ALA-458 AND LEU-480.

Entry informationi

Entry nameiCATF_HUMAN
AccessioniPrimary (citable) accession number: Q9UBX1
Secondary accession number(s): B2R964
, O95240, Q9NSU4, Q9UKQ5
Entry historyi
Integrated into UniProtKB/Swiss-Prot: January 23, 2001
Last sequence update: April 30, 2000
Last modified: March 31, 2015
This is version 140 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. Human chromosome 11
    Human chromosome 11: entries, gene names and cross-references to MIM
  2. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  3. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  4. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  5. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  6. Peptidase families
    Classification of peptidase families and list of entries
  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.