ID TOP1_XENLA Reviewed; 829 AA. AC P41512; DT 01-NOV-1995, integrated into UniProtKB/Swiss-Prot. DT 01-NOV-1995, sequence version 1. DT 27-MAR-2024, entry version 122. DE RecName: Full=DNA topoisomerase 1; DE EC=5.6.2.1 {ECO:0000255|PROSITE-ProRule:PRU10130}; DE AltName: Full=DNA topoisomerase I; GN Name=top1; OS Xenopus laevis (African clawed frog). OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia; OC Batrachia; Anura; Pipoidea; Pipidae; Xenopodinae; Xenopus; Xenopus. OX NCBI_TaxID=8355; RN [1] RP NUCLEOTIDE SEQUENCE [MRNA]. RX PubMed=8836188; DOI=10.1093/nar/24.18.3593; RA Pandit S.D., Richard R.E., Sternglanz R., Bogenhagen D.F.; RT "Cloning and characterization of the gene for the somatic form of DNA RT topoisomerase I from Xenopus laevis."; RL Nucleic Acids Res. 24:3593-3600(1996). CC -!- FUNCTION: Releases the supercoiling and torsional tension of DNA CC introduced during the DNA replication and transcription by transiently CC cleaving and rejoining one strand of the DNA duplex. Introduces a CC single-strand break via transesterification at a target site in duplex CC DNA. The scissile phosphodiester is attacked by the catalytic tyrosine CC of the enzyme, resulting in the formation of a DNA-(3'-phosphotyrosyl)- CC enzyme intermediate and the expulsion of a 5'-OH DNA strand. TThe free CC DNA strand then rotates around the intact phosphodiester bond on the CC opposing strand, thus removing DNA supercoils. Finally, in the CC religation step, the DNA 5'-OH attacks the covalent intermediate to CC expel the active-site tyrosine and restore the DNA phosphodiester CC backbone. May play a role in the circadian transcription of the core CC circadian clock component BMAL1. {ECO:0000250|UniProtKB:P11387}. CC -!- CATALYTIC ACTIVITY: CC Reaction=ATP-independent breakage of single-stranded DNA, followed by CC passage and rejoining.; EC=5.6.2.1; Evidence={ECO:0000255|PROSITE- CC ProRule:PRU10130}; CC -!- SUBUNIT: Monomer. {ECO:0000250|UniProtKB:P11387}. CC -!- SUBCELLULAR LOCATION: Nucleus {ECO:0000250|UniProtKB:P11387}. CC -!- MISCELLANEOUS: Eukaryotic topoisomerase I and II can relax both CC negative and positive supercoils, whereas prokaryotic enzymes relax CC only negative supercoils. CC -!- SIMILARITY: Belongs to the type IB topoisomerase family. {ECO:0000305}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; L07777; AAB36608.1; -; mRNA. DR PIR; S72366; S72366. DR RefSeq; NP_001084031.1; NM_001090562.1. DR AlphaFoldDB; P41512; -. DR SMR; P41512; -. DR BioGRID; 100588; 1. DR MaxQB; P41512; -. DR GeneID; 399263; -. DR KEGG; xla:399263; -. DR AGR; Xenbase:XB-GENE-950006; -. DR CTD; 399263; -. DR Xenbase; XB-GENE-950006; top1.L. DR OrthoDB; 10940at2759; -. DR Proteomes; UP000186698; Chromosome 9_10L. DR Bgee; 399263; Expressed in gastrula and 19 other cell types or tissues. DR GO; GO:0005694; C:chromosome; IEA:InterPro. DR GO; GO:0005634; C:nucleus; IEA:UniProtKB-SubCell. DR GO; GO:0003917; F:DNA topoisomerase type I (single strand cut, ATP-independent) activity; IEA:UniProtKB-EC. DR GO; GO:0000978; F:RNA polymerase II cis-regulatory region sequence-specific DNA binding; ISS:UniProtKB. DR GO; GO:0006338; P:chromatin remodeling; ISS:UniProtKB. DR GO; GO:0032922; P:circadian regulation of gene expression; ISS:UniProtKB. DR GO; GO:0006265; P:DNA topological change; IEA:InterPro. DR CDD; cd00659; Topo_IB_C; 1. DR CDD; cd03488; Topoisomer_IB_N_htopoI_like; 1. DR Gene3D; 1.10.132.10; -; 1. DR Gene3D; 2.170.11.10; DNA Topoisomerase I, domain 2; 1. DR Gene3D; 1.10.10.41; Yeast DNA topoisomerase - domain 1; 1. DR InterPro; IPR011010; DNA_brk_join_enz. DR InterPro; IPR013034; DNA_topo_DNA_db_N_dom1. DR InterPro; IPR013030; DNA_topo_DNA_db_N_dom2. DR InterPro; IPR001631; TopoI. DR InterPro; IPR018521; TopoI_AS. DR InterPro; IPR025834; TopoI_C_dom. DR InterPro; IPR014711; TopoI_cat_a-hlx-sub_euk. DR InterPro; IPR014727; TopoI_cat_a/b-sub_euk. DR InterPro; IPR013500; TopoI_cat_euk. DR InterPro; IPR008336; TopoI_DNA-bd_euk. DR InterPro; IPR036202; TopoI_DNA-bd_euk_N_sf. DR InterPro; IPR013499; TopoI_euk. DR InterPro; IPR048045; Topoisomer_I_DNA-bd. DR PANTHER; PTHR10290:SF5; DNA TOPOISOMERASE 1; 1. DR PANTHER; PTHR10290; DNA TOPOISOMERASE I; 1. DR Pfam; PF14370; Topo_C_assoc; 1. DR Pfam; PF01028; Topoisom_I; 1. DR Pfam; PF02919; Topoisom_I_N; 1. DR PRINTS; PR00416; EUTPISMRASEI. DR SMART; SM00435; TOPEUc; 1. DR SUPFAM; SSF56349; DNA breaking-rejoining enzymes; 1. DR SUPFAM; SSF46596; Eukaryotic DNA topoisomerase I, dispensable insert domain; 1. DR SUPFAM; SSF56741; Eukaryotic DNA topoisomerase I, N-terminal DNA-binding fragment; 1. DR PROSITE; PS00176; TOPO_IB_1; 1. DR PROSITE; PS52038; TOPO_IB_2; 1. PE 2: Evidence at transcript level; KW Biological rhythms; DNA-binding; Isomerase; Nucleus; Reference proteome; KW Topoisomerase. FT CHAIN 1..829 FT /note="DNA topoisomerase 1" FT /id="PRO_0000145204" FT DOMAIN 488..821 FT /note="Topo IB-type catalytic" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01382" FT REGION 1..248 FT /note="Disordered" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT REGION 481..482 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT REGION 544..549 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT REGION 641..643 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT COMPBIAS 33..164 FT /note="Basic and acidic residues" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT COMPBIAS 173..248 FT /note="Basic and acidic residues" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT ACT_SITE 779 FT /note="O-(3'-phospho-DNA)-tyrosine intermediate" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01382, FT ECO:0000255|PROSITE-ProRule:PRU10130" FT SITE 372 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 420 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 468 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 499 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 557 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 588 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 630 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 688 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 706 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" SQ SEQUENCE 829 AA; 98231 MW; 8D1FE4252A916219 CRC64; MSEDHVQNDS QIEAVFRVND SHKHKKDKEH RHKEHKKDKD REKSKHNNSE HRDPSEKKHK DKHKNNDKHR EKDGEKHRER DGEKHRDKNG EKHRDGEKHK EKDIEKHKEV EKHRVKDGEK HKEKDVEKHK EKDVEKHRDG EKHKHRDKDR EKKKEEKMKS SSGGVKVKKE NGFSSPVRVK DEPEDQGFYV SPKENKAMKR PREDDEDYKP KKIKSEDDKK GKKRKQEEED IKPKKKSKAK GNEEGVKKKK VKKEEEEKWK WWEEERHRDG IKWKFLEHKG PVFAPPYEPV PDNVKFYYDG NLVKLSPKAE EVATFFAKML DHEYTTKDIF RKNFFKDWKK EMTTDERNLI TNLSKCDFNA MSLYFKEQSE ARKNMTKEEK LKIKAENERL LQEYGYCIMD NHKERIANFR IEPPGLFRGR GDHPKMGKLK KRIMPEDIII NCSKDSKIPV APAGHKWKEV RHDGKVTWLV SWTENIQGSI KYIMLNPSSR IKGEKDWQKY ETARRLKMCV EKIRNTYKED WKSKEMKVRQ RAVALYFIDK LALRAGNEKE EGETADTVGC CSLRVEHINL FQELDGQEFV VEFDFPGKDS IRYYNKVPVE KRVFKNLQLF MENKQPDDDL FDRLNTSILN KHLQDLMEGL TAKVFRTYNA SITLQQQLDE LTNSDDNVPA KILSYNRANR AVAILCNHQR APPKTFEKSM MNLQGKIDAK KDQLADARRE FKSAKADAKV RRDEKTKKLV ESKKKAVQRI EEQLMKLEVQ ATDREENKQI ALGTSKLNYL DPRISVAWCK KYGVPIEKIY NKTQRKNLLG PSIWQTTTSN FNAEQRCFS //