P41512 (TOP1_XENLA) 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

Gene names

Name:

top1

Organism

Xenopus laevis (African clawed frog)

Taxonomic identifier

8355 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Amphibia › Batrachia › Anura › Mesobatrachia › Pipoidea › Pipidae › Xenopodinae › Xenopus › Xenopus

Protein attributes

Sequence length	829 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.
Subunit structure	Monomer By similarity.
Subcellular location	Nucleus By similarity.
Miscellaneous	Eukaryotic topoisomerase I and II can relax both negative and positive supercoils, whereas prokaryotic enzymes relax only negative supercoils.
Sequence similarities	Belongs to the type IB topoisomerase family.

Ontologies

Keywords
Cellular component	Nucleus
Ligand	ATP-binding DNA-binding Nucleotide-binding
Molecular function	Isomerase Topoisomerase
Gene Ontology (GO)
Biological process	DNA topological change Inferred from electronic annotation. Source: InterPro
Cellular component	chromosome Inferred from electronic annotation. Source: InterPro nucleus Inferred from electronic annotation. Source: UniProtKB-SubCell
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 electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 829	829	DNA topoisomerase 1		PRO_0000145204
Sites
	Active site	779	1	O-(3'-phospho-DNA)-tyrosine intermediate By similarity

Sequences

	Sequence		Length	Mass (Da)
	P41512 [UniParc]. Last modified November 1, 1995. Version 1. Checksum: 8D1FE4252A916219	FASTA	829	98,231
	10 20 30 40 50 60 MSEDHVQNDS QIEAVFRVND SHKHKKDKEH RHKEHKKDKD REKSKHNNSE HRDPSEKKHK 70 80 90 100 110 120 DKHKNNDKHR EKDGEKHRER DGEKHRDKNG EKHRDGEKHK EKDIEKHKEV EKHRVKDGEK 130 140 150 160 170 180 HKEKDVEKHK EKDVEKHRDG EKHKHRDKDR EKKKEEKMKS SSGGVKVKKE NGFSSPVRVK 190 200 210 220 230 240 DEPEDQGFYV SPKENKAMKR PREDDEDYKP KKIKSEDDKK GKKRKQEEED IKPKKKSKAK 250 260 270 280 290 300 GNEEGVKKKK VKKEEEEKWK WWEEERHRDG IKWKFLEHKG PVFAPPYEPV PDNVKFYYDG 310 320 330 340 350 360 NLVKLSPKAE EVATFFAKML DHEYTTKDIF RKNFFKDWKK EMTTDERNLI TNLSKCDFNA 370 380 390 400 410 420 MSLYFKEQSE ARKNMTKEEK LKIKAENERL LQEYGYCIMD NHKERIANFR IEPPGLFRGR 430 440 450 460 470 480 GDHPKMGKLK KRIMPEDIII NCSKDSKIPV APAGHKWKEV RHDGKVTWLV SWTENIQGSI 490 500 510 520 530 540 KYIMLNPSSR IKGEKDWQKY ETARRLKMCV EKIRNTYKED WKSKEMKVRQ RAVALYFIDK 550 560 570 580 590 600 LALRAGNEKE EGETADTVGC CSLRVEHINL FQELDGQEFV VEFDFPGKDS IRYYNKVPVE 610 620 630 640 650 660 KRVFKNLQLF MENKQPDDDL FDRLNTSILN KHLQDLMEGL TAKVFRTYNA SITLQQQLDE 670 680 690 700 710 720 LTNSDDNVPA KILSYNRANR AVAILCNHQR APPKTFEKSM MNLQGKIDAK KDQLADARRE 730 740 750 760 770 780 FKSAKADAKV RRDEKTKKLV ESKKKAVQRI EEQLMKLEVQ ATDREENKQI ALGTSKLNYL 790 800 810 820 DPRISVAWCK KYGVPIEKIY NKTQRKNLLG PSIWQTTTSN FNAEQRCFS

References

[1]	"Cloning and characterization of the gene for the somatic form of DNA topoisomerase I from Xenopus laevis." Pandit S.D., Richard R.E., Sternglanz R., Bogenhagen D.F. Nucleic Acids Res. 24:3593-3600(1996) [PubMed: 8836188] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	L07777 mRNA. Translation: AAB36608.1.
PIR	S72366.
RefSeq	NP_001084031.1. NM_001090562.1.
UniGene	Xl.62.
3D structure databases
ProteinModelPortal	P41512.
SMR	P41512. Positions 255-808.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
GeneID	399263.
KEGG	xla:399263.
Organism-specific databases
CTD	399263.
Xenbase	XB-GENE-950006. top1.1.
Phylogenomic databases
HOVERGEN	HBG007988.
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...

Entry information

Entry name

TOP1_XENLA

Accession

Primary (citable) accession number: P41512

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1995
Last sequence update:	November 1, 1995
Last modified:	November 16, 2011
This is version 71 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program