ID TOP1M_RAT Reviewed; 593 AA. AC Q6IM78; DT 22-SEP-2009, integrated into UniProtKB/Swiss-Prot. DT 05-JUL-2004, sequence version 1. DT 27-MAR-2024, entry version 129. DE RecName: Full=DNA topoisomerase I, mitochondrial; DE Short=TOP1mt; DE EC=5.6.2.1; DE Flags: Precursor; GN Name=Top1mt; OS Rattus norvegicus (Rat). OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; OC Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea; Muridae; OC Murinae; Rattus. OX NCBI_TaxID=10116; RN [1] RP NUCLEOTIDE SEQUENCE [MRNA]. RX PubMed=15096574; DOI=10.1093/nar/gkh525; RA Zhang H., Meng L.-H., Zimonjic D.B., Popescu N.C., Pommier Y.; RT "Thirteen-exon-motif signature for vertebrate nuclear and mitochondrial RT type IB topoisomerases."; RL Nucleic Acids Res. 32:2087-2092(2004). CC -!- FUNCTION: Releases the supercoiling and torsional tension of DNA CC introduced during duplication of mitochondrial DNA 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. The 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 (By similarity). {ECO:0000250}. CC -!- CATALYTIC ACTIVITY: CC Reaction=ATP-independent breakage of single-stranded DNA, followed by CC passage and rejoining.; EC=5.6.2.1; CC -!- COFACTOR: CC Name=Ca(2+); Xref=ChEBI:CHEBI:29108; Evidence={ECO:0000250}; CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000250}; CC Note=Divalent metal ions (calcium or magnesium). {ECO:0000250}; CC -!- SUBCELLULAR LOCATION: Mitochondrion {ECO:0000250}. 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; BK001786; DAA02296.1; -; mRNA. DR RefSeq; NP_001002798.1; NM_001002798.1. DR AlphaFoldDB; Q6IM78; -. DR SMR; Q6IM78; -. DR STRING; 10116.ENSRNOP00000009965; -. DR PhosphoSitePlus; Q6IM78; -. DR PaxDb; 10116-ENSRNOP00000009965; -. DR Ensembl; ENSRNOT00000009965.5; ENSRNOP00000009965.3; ENSRNOG00000007500.6. DR Ensembl; ENSRNOT00055043898; ENSRNOP00055035882; ENSRNOG00055025377. DR Ensembl; ENSRNOT00060033739; ENSRNOP00060027630; ENSRNOG00060019253. DR Ensembl; ENSRNOT00065015636; ENSRNOP00065011805; ENSRNOG00065009714. DR GeneID; 300029; -. DR KEGG; rno:300029; -. DR UCSC; RGD:1303177; rat. DR AGR; RGD:1303177; -. DR CTD; 116447; -. DR RGD; 1303177; Top1mt. DR eggNOG; KOG0981; Eukaryota. DR GeneTree; ENSGT00940000162943; -. DR InParanoid; Q6IM78; -. DR OMA; RNYIDPR; -. DR OrthoDB; 10940at2759; -. DR PhylomeDB; Q6IM78; -. DR TreeFam; TF105281; -. DR PRO; PR:Q6IM78; -. DR Proteomes; UP000002494; Chromosome 7. DR Bgee; ENSRNOG00000007500; Expressed in testis and 19 other cell types or tissues. DR ExpressionAtlas; Q6IM78; baseline and differential. DR GO; GO:0005694; C:chromosome; IEA:InterPro. DR GO; GO:0042645; C:mitochondrial nucleoid; ISO:RGD. DR GO; GO:0005654; C:nucleoplasm; IEA:Ensembl. DR GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW. DR GO; GO:0003917; F:DNA topoisomerase type I (single strand cut, ATP-independent) activity; IBA:GO_Central. DR GO; GO:0006260; P:DNA replication; IBA:GO_Central. DR GO; GO:0006265; P:DNA topological change; IBA:GO_Central. 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; 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; DNA TOPOISOMERASE I; 1. DR PANTHER; PTHR10290:SF1; DNA TOPOISOMERASE I, MITOCHONDRIAL; 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; PS52038; TOPO_IB_2; 1. DR Genevisible; Q6IM78; RN. PE 2: Evidence at transcript level; KW DNA-binding; Isomerase; Mitochondrion; Reference proteome; Topoisomerase; KW Transit peptide. FT TRANSIT 1..43 FT /note="Mitochondrion" FT /evidence="ECO:0000250" FT CHAIN 44..593 FT /note="DNA topoisomerase I, mitochondrial" FT /id="PRO_0000384395" FT DOMAIN 261..593 FT /note="Topo IB-type catalytic" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01382" FT REGION 254..255 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT REGION 317..322 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT REGION 414..416 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT ACT_SITE 551 FT /note="O-(3'-phospho-DNA)-tyrosine intermediate" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01382" FT SITE 145 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 193 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 241 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 272 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 330 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 361 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 403 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 461 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" FT SITE 479 FT /note="Interaction with DNA" FT /evidence="ECO:0000250" SQ SEQUENCE 593 AA; 69011 MW; 6B691D668970BD9E CRC64; MLLLWLRALC RRFQHVPRRV PSRQVSRGSK ASRAGWGETS KSSVKWKQLE HKGPCFAPAY EPLPDGVRFF YDGKPVRLSL AAEEVATFYG KMLHLECTTK EVFRRNFFSD WQKEMTAEER KLITHLDKCD FSEIHRHFME RAEARRTLPR EQKQKLKEEA EKLQQEFGYC ILDGHREKIG NFKTEPPGLF RGRGDHPKMG MLKRRVMPED VVINCSRDSK IPEPPAGHQW KEVRSDNTVM WLAAWVENIQ NSFKYIILNP SSKPKGEMDW QKYEVARRLK GVVDKIRAQY QADWKSPEMK KRQLAVALYF IDKLALRTGN EKEEGETADT VGCCSLRVEH VRLHTPADGQ EHVVELDFLG KDSIRYKNHV TVEKLVFQNL QHFMEDKDPR DDLFDALTTS SLNKHLQDLM EGLTAKVFRT YNASITLQEQ LRVLTRAEDS LTCKVLAYNR ANRAVAVLCN HQRAIPKTFE ESMQTLQKKI ETKKAQVAEA QVELQKAETD LRMRGDSKSK SFLQKQQRLL KLEEQLARLC TKATDKEENK QVALGTAKLN YLDPRISIAW CKRFGVPVEK IYNKTQRERF AWAFNQAGED FEF //