Reviewed, UniProtKB/Swiss-Prot Q07050 (TOP1_CRIGR)

Names and origin

Protein names

Recommended name:
    DNA topoisomerase 1
    EC=5.99.1.2
Alternative name(s):
    DNA topoisomerase I

Gene names

Name:	TOP1
Synonyms:	TOP-1

Organism

Cricetulus griseus (Chinese hamster)

Taxonomic identifier

10029 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Glires › Rodentia › Sciurognathi › Muroidea › Cricetidae › Cricetinae › Cricetulus

Protein attributes

Sequence length	767 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at transcript level.

General annotation (Comments)

Function	The reaction catalyzed by topoisomerases leads to the conversion of one topological isomer of DNA to another.
Catalytic activity	ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.
Enzyme regulation	Specifically inhibited by camptothecin (CPT), a plant alkaloid with antitumor activity.
Subunit structure	Monomer.
Subcellular location	Nucleus › nucleolus. Nucleus › nucleoplasm. Note: Diffuse nuclear localization with some enrichment in nucleoli. On CPT treatment, cleared from nucleoli into nucleoplasm. Sumolyated forms found in both nucleoplasm and nucleoli By similarity.
Post-translational modification	Sumoylated. Lys-119 is the main site of sumoylation. Sumoylation plays a role in partitioning TOP1 between nucleoli and nucleoplasm. Levels are dramatically increased on camptothecin (CPT) treatment By similarity.
Miscellaneous	Eukaryotic topoisomerase I and II can relax both negative and positive supercoils, whereas prokaryotic enzymes relax only negative supercoils. When a topoisomerase transiently breaks a DNA backbone bond, it simultaneously forms a protein-DNA link, in which a tyrosyl oxygen in the enzyme is joined to a DNA phosphorus at one end of the enzyme-severed DNA strand.
Sequence similarities	Belongs to the eukaryotic type I topoisomerase family.

Ontologies

Keywords
Cellular component	Nucleus
Ligand	ATP-binding DNA-binding Nucleotide-binding
Molecular function	Isomerase Topoisomerase
PTM	Acetylation Isopeptide bond Phosphoprotein Ubl conjugation
Gene Ontology (GO)
Biological process	DNA topological change Inferred from electronic annotation. Source: InterPro DNA unwinding during replication Inferred from electronic annotation. Source: InterPro
Cellular component	chromosome Inferred from electronic annotation. Source: InterPro nucleolus Inferred from sequence or structural similarity. Source: UniProtKB nucleoplasm Inferred from sequence or structural similarity. Source: UniProtKB
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 sequence or structural similarity. Source: UniProtKB chromatin binding Inferred from sequence or structural similarity. Source: UniProtKB protein binding Inferred from sequence or structural similarity. Source: UniProtKB
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Initiator methionine	1	1	Removed By similarity
	Chain	2 – 767	766	DNA topoisomerase 1		PRO_0000145200
Regions
	Compositional bias	23 – 206	184	Lys-rich
Sites
	Active site	725	1	O-(3'-phospho-DNA)-tyrosine intermediate By similarity
Amino acid modifications
	Modified residue	2	1	N-acetylserine By similarity
	Modified residue	114	1	Phosphoserine By similarity
	Modified residue	282	1	N6-acetyllysine By similarity
	Cross-link	105		Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO) Probable
	Cross-link	119		Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO) By similarity
	Cross-link	155		Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO) Probable
Natural variations
	Natural variant	505	1	S → G in CPT-resistant cell.

Sequences

	Sequence		Length	Mass (Da)
	Q07050-1 [UniParc]. Last modified October 1, 1994. Version 1. Checksum: 347336D424EF35A9	FASTA	767	90,868
	10 20 30 40 50 60 MSGDHLHNDS QIEADFRLND SHKHKDKHKD REHRHKEHKK DKEKDREKSK HSNSEHKDSE 70 80 90 100 110 120 KKHKEKEKTK HKDGSSEKHK DKHKDRDKEK RKEEKIRASG DAKIKKEKEN GFSSPPRIKD 130 140 150 160 170 180 EPDDDGYFAP PKEDIKPLKR PRDEDDADYK PKKIKTEDIK KEKKRKLEEE EDGKLKKTKN 190 200 210 220 230 240 KDKDKKGAES DNKKKKPKKE EEQKWKWWEE ERYPEGIKWK FLEHKGPVFA PPYEPLPEGV 250 260 270 280 290 300 KFYYDGKVMK LSPKAEEVAT FFAKMLDHEY TTKEIFRKNF FKDWRKEMTN DEKNVITNLS 310 320 330 340 350 360 KCDFTQMSQY FKDQSEARKQ MSKEEKLKIK EENEKLLKEY GFCVMDNHRE RIANFKIEPP 370 380 390 400 410 420 GLFRGRGNHP KMGMLKRRIM PEDIIINCSK DAKVPSPPPG HKWKEVRHDN KVTWLVSWTE 430 440 450 460 470 480 NIQGSIKYIM LNPSSRIKGE KDWQKYETAR RLKKCVDKIR NQYREDWKSK EMKVRQRAVA 490 500 510 520 530 540 LYFIDKLALR AGNEKEEGET ADTVSCCSLR VEHINLHPEL DGQEYVVEFD FPGKDSIRYY 550 560 570 580 590 600 NKVPVEKRVF KNLQLFMENK QPEDDLFDRL NTGILNKHLQ DLMEGLTAKV FRTYNASITL 610 620 630 640 650 660 QQQLKELTAP DENVPAKILS YNRANRAVAI LCNHQRAPPK TFEKSMMNLQ SKIDAKKDQL 670 680 690 700 710 720 ADARRDLKSA KADAKVMKDA KTKKVVESKK KAVQRLEEQL MKLEVQATDR EENKQIALGT 730 740 750 760 SKLNYLDPRI TVAWCKKWGV PIEKIYNKTQ REKFAWAIDM TDEDYEF

References

[1]

"Cloning of Chinese hamster DNA topoisomerase I cDNA and identification of a single point mutation responsible for camptothecin resistance." Tanizawa A., Bertrand R., Kohlhagen G., Tabuchi A., Jenkins J., Pommier Y. J. Biol. Chem. 268:25463-25468(1993) [PubMed: 8244980] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].

Cross-references

Sequence databases
EMBL GenBank DDBJ	Z21624 mRNA. Translation: CAA79747.1. Z21625 mRNA. Translation: CAA79748.1.
PIR	A49546.
3D structure databases
SMR	Q07050. Positions 201-767.
ModBase	Search...
Phylogenomic databases
HOVERGEN	Q07050.
Enzyme and pathway databases
BRENDA	5.99.1.2. 18.
Family and domain databases
InterPro	IPR011010. DNA_brk_join_enz. IPR018521. TopoI_AS. IPR001631. TopoI_C. IPR013499. TopoI_C_euk. IPR014711. TopoI_cat_a-hlx-sub_euk. IPR014727. TopoI_cat_a/b-sub_euk. IPR013030. TopoI_DNA-bd_mixed-a/b_euk. IPR008336. TopoI_DNA_bd_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:2.170.11.10. TopoI_DNA-bd_mixed-a/b_euk. 1 hit.
Pfam	PF02919. Topoisom_I_N. 1 hit. [Graphical view]
PRINTS	PR00416. EUTPISMRASEI.
SMART	SM00435. TOPEUc. 1 hit. [Graphical view]
PROSITE	PS00176. TOPOISOMERASE_I_EUK. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

TOP1_CRIGR

Accession

Primary (citable) accession number: Q07050

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 1, 1994
Last sequence update:	October 1, 1994
Last modified:	February 9, 2010
This is version 62 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HPI (Human Proteome Initiative)