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O17966 (TOP1_CAEEL) Reviewed, UniProtKB/Swiss-Prot

Last modified July 9, 2014. Version 102. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (2) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Alt products·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
DNA topoisomerase 1

EC=5.99.1.2
Alternative name(s):
DNA topoisomerase I
Short name=topoI
Gene names
Name:top-1
ORF Names:M01E5.5
OrganismCaenorhabditis elegans [Reference proteome]
Taxonomic identifier6239 [NCBI]
Taxonomic lineageEukaryotaMetazoaEcdysozoaNematodaChromadoreaRhabditidaRhabditoideaRhabditidaePeloderinaeCaenorhabditis

Protein attributes

Sequence length806 AA.
Sequence statusComplete.
Protein existenceEvidence at transcript level

General annotation (Comments)

Function

Releases the supercoiling and torsional tension of DNA introduced during the DNA replication and transcription by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(3'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 5'-OH DNA strand. The free DNA strand then undergoes passage around the unbroken strand thus removing DNA supercoils. Finally, in the religation step, the DNA 5'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone By similarity.

Catalytic activity

ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.

Subcellular location

Nucleus By similarity.

Developmental stage

Isoform a is only expressed in embryos. Isoform b is present at all developmental stages. Ref.2

Miscellaneous

Eukaryotic topoisomerase I and II can relax both negative and positive supercoils, whereas prokaryotic enzymes relax only negative supercoils By similarity.

Sequence similarities

Belongs to the type IB topoisomerase family.

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]
Isoform a (identifier: O17966-1)

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.
Isoform b (identifier: O17966-2)

The sequence of this isoform differs from the canonical sequence as follows:
     134-205: Missing.
Note: Predominant isoform.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 806806DNA topoisomerase 1
PRO_0000330482

Regions

Region467 – 4682Interaction with DNA By similarity
Region530 – 5356Interaction with DNA By similarity
Region634 – 6363Interaction with DNA By similarity

Sites

Active site7611O-(3'-phospho-DNA)-tyrosine intermediate By similarity
Site3581Interaction with DNA By similarity
Site4061Interaction with DNA By similarity
Site4541Interaction with DNA By similarity
Site4851Interaction with DNA By similarity
Site5431Interaction with DNA By similarity
Site5811Interaction with DNA By similarity
Site6231Interaction with DNA By similarity
Site6811Interaction with DNA By similarity
Site6991Interaction with DNA By similarity

Natural variations

Alternative sequence134 – 20572Missing in isoform b.
VSP_033045

Experimental info

Sequence conflict1721E → K in CAA65537. Ref.1

Sequences

Sequence LengthMass (Da)Tools
Isoform a [UniParc].

Last modified January 1, 1998. Version 1.
Checksum: 5979AD386DEBD004

FASTA80694,030
        10         20         30         40         50         60 
MSVVSNHHSN GNGNSTVYDT NGNDEIKKEV KDEPMASDSE VPFGELMKRD KKEKKQKKRK 

        70         80         90        100        110        120 
AESGSDEDDY KPEKRKSSAK NGKKKDVGSD SEDDYKPEKK KSKKNNKKKA QESSEDDDEE 

       130        140        150        160        170        180 
SEGDVSEEDV KPQIHSDDEL EEEDEAPTTD DEEEQKRKEK ERRKKEKREK KERKEKKRLE 

       190        200        210        220        230        240 
KENRKIKEED DEDSDDEDDE KAKKKKRKSK GAEKSKPSTS KKDAGGKKEP PKKKVKKEED 

       250        260        270        280        290        300 
IEDIWEWWKE EKKPAGVKWN SLQHCGPLFA PPYIPLPSHV HFKYGGEKMK LTLETEEIAQ 

       310        320        330        340        350        360 
FYAGVLDHEY STKEAFNKNF MKDWRKVMTV EERERIHDLK KCDFRAIDAY QKEQREIRKA 

       370        380        390        400        410        420 
MTKEEKLKIK EEKEAEVKIY GIAIIDGHRQ KVANFRIEPP GVFRGRGGHP KMGLIKKRIM 

       430        440        450        460        470        480 
PEDVIINCGK DTEIPKPPPG HKWKEVRHDN TVTWLCSWTE SVLGQNKYIM LNPSSKIKGE 

       490        500        510        520        530        540 
KDFEKYETAR RLKKKIGGIR ERYTDDFKSK EMRVRQRATA LYFIDKLALR AGNEKDVDEA 

       550        560        570        580        590        600 
ADTVGCCSLR VEHIKLFDSA KLNEDDKKEK EFVVEFDFLG KDSIRYFNRV SVEKRVYKNL 

       610        620        630        640        650        660 
KIFMEGKAPS DDLFDRLDTA TLNDHLRSLM DGLTVKVFRT YNASITLQEQ LIKLTNPKDN 

       670        680        690        700        710        720 
VAAKILSYNR ANRQVAILCN HQRAVSKGFD ESMQKLEQKI KDKKKEVKEA EAALKSARGA 

       730        740        750        760        770        780 
EKEKAQKKYD RLKEQLKKLK ISRTDKDENK QIALGTSKLN YIDPRITVAW CKKFEVPLEK 

       790        800 
VFTKTHREKF RWAIDMTNSS DEEYVF 

« Hide

Isoform b [UniParc].

Checksum: 1BE2C2FA8E492FF4
Show »

FASTA73485,089

References

« Hide 'large scale' references
[1]"cDNA cloning, expression, and chromosomal localization of Caenorhabditis elegans DNA topoisomerase I."
Kim J., Kim Y.-C., Lee J.H., Jang Y.J., Chung I.K., Koo H.-S.
Eur. J. Biochem. 237:367-372(1996) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM A).
Strain: Bristol N2.
[2]"Alternative splicing in the Caenorhabditis elegans DNA topoisomerase I gene."
Lee M.H., Jang Y.J., Koo H.-S.
Biochim. Biophys. Acta 1396:207-214(1998) [PubMed] [Europe PMC] [Abstract]
Cited for: SEQUENCE REVISION, ALTERNATIVE SPLICING, DEVELOPMENTAL STAGE.
Strain: Bristol N2.
[3]"Genome sequence of the nematode C. elegans: a platform for investigating biology."
The C. elegans sequencing consortium
Science 282:2012-2018(1998) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: Bristol N2.
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
X96762 mRNA. Translation: CAA65537.1.
Z93385 Genomic DNA. Translation: CAB07639.1.
Z93385 Genomic DNA. Translation: CAB07640.1.
PIRS65469.
T23647.
T23648.
RefSeqNP_001021578.1. NM_001026407.5. [O17966-2]
NP_493337.1. NM_060936.5. [O17966-1]
UniGeneCel.17282.

3D structure databases

ProteinModelPortalO17966.
SMRO17966. Positions 245-806.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

STRING6239.M01E5.5a.

Proteomic databases

PaxDbO17966.
PRIDEO17966.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblMetazoaM01E5.5a; M01E5.5a; WBGene00006595. [O17966-1]
GeneID266847.
KEGGcel:CELE_M01E5.5.
UCSCM01E5.5b. c. elegans. [O17966-1]

Organism-specific databases

CTD266847.
WormBaseM01E5.5a; CE12282; WBGene00006595; top-1.
M01E5.5b; CE12284; WBGene00006595; top-1.

Phylogenomic databases

eggNOGCOG3569.
GeneTreeENSGT00390000016347.
HOGENOMHOG000105469.
InParanoidO17966.
KOK03163.
OMAREKFNWA.
OrthoDBEOG7CVPX5.
PhylomeDBO17966.

Family and domain databases

Gene3D1.10.10.41. 1 hit.
1.10.132.10. 1 hit.
2.170.11.10. 2 hits.
3.90.15.10. 1 hit.
InterProIPR011010. DNA_brk_join_enz.
IPR013034. DNA_topo_domain1.
IPR001631. TopoI.
IPR018521. TopoI_AS.
IPR025834. TopoI_C_dom.
IPR014711. TopoI_cat_a-hlx-sub_euk.
IPR014727. TopoI_cat_a/b-sub_euk.
IPR013500. TopoI_cat_euk.
IPR008336. TopoI_DNA-bd_euk.
IPR013030. TopoI_DNA-bd_mixed-a/b_euk.
IPR013499. TopoI_euk.
[Graphical view]
PfamPF14370. Topo_C_assoc. 1 hit.
PF01028. Topoisom_I. 1 hit.
PF02919. Topoisom_I_N. 1 hit.
[Graphical view]
PRINTSPR00416. EUTPISMRASEI.
SMARTSM00435. TOPEUc. 1 hit.
[Graphical view]
SUPFAMSSF56349. SSF56349. 2 hits.
SSF56741. SSF56741. 1 hit.
PROSITEPS00176. TOPOISOMERASE_I_EUK. 1 hit.
[Graphical view]
ProtoNetSearch...

Other

NextBio953260.

Entry information

Entry nameTOP1_CAEEL
AccessionPrimary (citable) accession number: O17966
Secondary accession number(s): O17965, Q27529
Entry history
Integrated into UniProtKB/Swiss-Prot: April 29, 2008
Last sequence update: January 1, 1998
Last modified: July 9, 2014
This is version 102 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programCaenorhabditis annotation project

Relevant documents

SIMILARITY comments

Index of protein domains and families

Caenorhabditis elegans

Caenorhabditis elegans: entries, gene names and cross-references to WormBase