O17966 (TOP1_CAEEL) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended 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

Organism

Caenorhabditis elegans

Taxonomic identifier

6239 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Nematoda › Chromadorea › Rhabditida › Rhabditoidea › Rhabditidae › Peloderinae › Caenorhabditis

Protein attributes

Sequence length	806 AA.
Sequence status	Complete.
Protein existence	Evidence 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 than 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.

Ontologies

Keywords
Cellular component	Nucleus
Coding sequence diversity	Alternative splicing
Ligand	ATP-binding DNA-binding Nucleotide-binding
Molecular function	Isomerase Topoisomerase
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Biological process	DNA topological change Inferred from Biological aspect of Ancestor. Source: RefGenome body morphogenesis Inferred from mutant phenotype. Source: WormBase determination of adult lifespan Inferred from mutant phenotype. Source: WormBase embryo development ending in birth or egg hatching Inferred from mutant phenotype. Source: WormBase gonad development Inferred from mutant phenotype. Source: WormBase growth Inferred from mutant phenotype. Source: WormBase locomotion Inferred from mutant phenotype. Source: WormBase meiotic chromosome segregation Inferred from mutant phenotype. Source: WormBase molting cycle, collagen and cuticulin-based cuticle Inferred from mutant phenotype. Source: WormBase morphogenesis of an epithelium Inferred from mutant phenotype. Source: WormBase nematode larval development Inferred from mutant phenotype. Source: WormBase oogenesis Inferred from mutant phenotype. Source: WormBase positive regulation of growth rate Inferred from mutant phenotype. Source: WormBase receptor-mediated endocytosis Inferred from mutant phenotype. Source: WormBase
Cellular component	chromosome Inferred from electronic annotation. Source: InterPro nucleolus Inferred from direct assay. Source: WormBase spindle pole centrosome Inferred from direct assay. Source: WormBase
Molecular function	ATP binding Inferred from electronic annotation. Source: UniProtKB-KW DNA topoisomerase (ATP-hydrolyzing) activity Inferred from electronic annotation. Source: InterPro DNA topoisomerase type I activity Inferred from direct assay Ref.1. Source: WormBase chromatin DNA binding Inferred from Biological aspect of Ancestor. Source: RefGenome
Complete GO annotation...

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 key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 806	806	DNA topoisomerase 1		PRO_0000330482
Sites
	Active site	761	1	O-(3'-phospho-DNA)-tyrosine intermediate By similarity
Natural variations
	Alternative sequence	134 – 205	72	Missing in isoform b.		VSP_033045
Experimental info
	Sequence conflict	172	1	E → K in CAA65537. Ref.1

Sequences

	Sequence		Length	Mass (Da)
	Isoform a [UniParc]. Last modified January 1, 1998. Version 1. Checksum: 5979AD386DEBD004	FASTA	806	94,030
	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
	Isoform b [UniParc]. Checksum: 1BE2C2FA8E492FF4	FASTA	734	85,089
	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 KPQKRKSKGA EKSKPSTSKK DAGGKKEPPK KKVKKEEDIE DIWEWWKEEK 190 200 210 220 230 240 KPAGVKWNSL QHCGPLFAPP YIPLPSHVHF KYGGEKMKLT LETEEIAQFY AGVLDHEYST 250 260 270 280 290 300 KEAFNKNFMK DWRKVMTVEE RERIHDLKKC DFRAIDAYQK EQREIRKAMT KEEKLKIKEE 310 320 330 340 350 360 KEAEVKIYGI AIIDGHRQKV ANFRIEPPGV FRGRGGHPKM GLIKKRIMPE DVIINCGKDT 370 380 390 400 410 420 EIPKPPPGHK WKEVRHDNTV TWLCSWTESV LGQNKYIMLN PSSKIKGEKD FEKYETARRL 430 440 450 460 470 480 KKKIGGIRER YTDDFKSKEM RVRQRATALY FIDKLALRAG NEKDVDEAAD TVGCCSLRVE 490 500 510 520 530 540 HIKLFDSAKL NEDDKKEKEF VVEFDFLGKD SIRYFNRVSV EKRVYKNLKI FMEGKAPSDD 550 560 570 580 590 600 LFDRLDTATL NDHLRSLMDG LTVKVFRTYN ASITLQEQLI KLTNPKDNVA AKILSYNRAN 610 620 630 640 650 660 RQVAILCNHQ RAVSKGFDES MQKLEQKIKD KKKEVKEAEA ALKSARGAEK EKAQKKYDRL 670 680 690 700 710 720 KEQLKKLKIS RTDKDENKQI ALGTSKLNYI DPRITVAWCK KFEVPLEKVF TKTHREKFRW 730 AIDMTNSSDE EYVF

References

	« Hide 'large scale' referencesShow '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: 8647074] [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: 9540836] [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: 9851916] [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.
PIR	S65469. T23647. T23648.
RefSeq	NP_001021578.1. NM_001026407.4. NP_493337.1. NM_060936.4.
UniGene	Cel.17282.
3D structure databases
HSSP	HSSP built from PDB template 1A35 based on UniProtKB P11387.
ProteinModelPortal	O17966.
SMR	O17966. Positions 245-806.
ModBase	Search...
Protein-protein interaction databases
STRING	O17966.
Proteomic databases
PRIDE	O17966.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
EnsemblMetazoa	M01E5.5a; M01E5.5a; M01E5.5.
GeneID	266847.
KEGG	cel:M01E5.5.
NMPDR	fig|6239.3.peg.3502.
UCSC	M01E5.5b. c. elegans.
Organism-specific databases
CTD	266847.
WormBase	M01E5.5a; CE12282; WBGene00006595; top-1. M01E5.5b; CE12284; WBGene00006595; top-1.
Phylogenomic databases
eggNOG	meNOG05029.
GeneTree	EMGT00050000002099.
HOGENOM	HBG521929.
InParanoid	O17966.
OMA	DERIANM.
PhylomeDB	O17966.
Gene expression databases
ArrayExpress	O17966.
Family and domain databases
InterPro	IPR011010. DNA_brk_join_enz. IPR013034. DNA_topo_domain1. IPR018521. TopoI_AS. IPR001631. TopoI_C. IPR013499. TopoI_C_euk. 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. IPR009054. TopoI_insert_euk. [Graphical view]
Gene3D	G3DSA:3.90.15.10. TopoI_cat_a-hlx-sub_euk. 1 hit. G3DSA:1.10.132.10. TopoI_cat_a/b-sub_euk. 1 hit. G3DSA:1.10.10.41. TopoI_DNA-bd_a-hlx_euk. 1 hit. G3DSA:2.170.11.10. TopoI_DNA-bd_mixed-a/b_euk. 2 hits.
KO	K03163.
Pfam	PF01028. Topoisom_I. 1 hit. PF02919. Topoisom_I_N. 1 hit. [Graphical view]
PRINTS	PR00416. EUTPISMRASEI.
SMART	SM00435. TOPEUc. 1 hit. [Graphical view]
SUPFAM	SSF56349. DNA_brk_join_enz. 1 hit. SSF46596. Topismrse_insert. 1 hit. SSF56741. TopoI_DNA_bd_euk. 1 hit.
PROSITE	PS00176. TOPOISOMERASE_I_EUK. 1 hit. [Graphical view]
ProtoNet	Search...
Other
NextBio	953260.

Entry information

Entry name

TOP1_CAEEL

Accession

Primary (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:	November 16, 2011
This is version 80 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Caenorhabditis annotation project