ID TOP1_VACCW Reviewed; 314 AA. AC P68698; P08585; DT 01-AUG-1988, integrated into UniProtKB/Swiss-Prot. DT 01-AUG-1988, sequence version 1. DT 02-SEP-2026, entry version 111. DE RecName: Full=DNA topoisomerase 1B; DE Short=TopIB; DE EC=5.6.2.1 {ECO:0000255|PROSITE-ProRule:PRU10130}; DE AltName: Full=DNA topoisomerase I; DE AltName: Full=Late protein H6; GN Name=OPG111; Synonyms=TOP1; OrderedLocusNames=VACWR104; ORFNames=H6R; OS Vaccinia virus (strain Western Reserve) (VACV) (Vaccinia virus (strain OS WR)). OC Viruses; Varidnaviria; Bamfordvirae; Nucleocytoviricota; Pokkesviricetes; OC Chitovirales; Poxviridae; Chordopoxvirinae; Orthopoxvirus; Vaccinia virus. OX NCBI_TaxID=10254; OH NCBI_TaxID=9913; Bos taurus (Bovine). RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RX PubMed=3021979; DOI=10.1128/jvi.60.2.436-449.1986; RA Rosel J.L., Earl P.L., Weir J.P., Moss B.; RT "Conserved TAAATG sequence at the transcriptional and translational RT initiation sites of vaccinia virus late genes deduced by structural and RT functional analysis of the HindIII H genome fragment."; RL J. Virol. 60:436-449(1986). RN [2] RP NUCLEOTIDE SEQUENCE, AND MUTAGENESIS. RX PubMed=8393454; DOI=10.1016/s0021-9258(18)82336-5; RA Klemperer N., Traktman P.; RT "Biochemical analysis of mutant alleles of the vaccinia virus topoisomerase RT I carrying targeted substitutions in a highly conserved domain."; RL J. Biol. Chem. 268:15887-15899(1993). RN [3] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RA Esposito J.J., Frace A.M., Sammons S.A., Olsen-Rasmussen M., Osborne J., RA Wohlhueter R.; RT "Sequencing of the coding region of Vaccinia-WR to an average 9-fold RT redundancy and an error rate of 0.16/10kb."; RL Submitted (FEB-2003) to the EMBL/GenBank/DDBJ databases. RN [4] RP PROTEIN SEQUENCE OF 1-22, AND IDENTIFICATION. RX PubMed=2823264; DOI=10.1073/pnas.84.21.7478; RA Shuman S., Moss B.; RT "Identification of a vaccinia virus gene encoding a type I DNA RT topoisomerase."; RL Proc. Natl. Acad. Sci. U.S.A. 84:7478-7482(1987). RN [5] RP ACTIVE SITE, AND MUTAGENESIS OF TYR-274. RX PubMed=15755148; DOI=10.1021/ja044182z; RA Gao R., Zhang Y., Choudhury A.K., Dedkova L.M., Hecht S.M.; RT "Analogues of vaccinia virus DNA topoisomerase I modified at the active RT site tyrosine."; RL J. Am. Chem. Soc. 127:3321-3331(2005). RN [6] RP FUNCTION. RX PubMed=16669621; DOI=10.1021/bi060133i; RA Nagarajan R., Stivers J.T.; RT "Major groove interactions of vaccinia Topo I provide specificity by RT optimally positioning the covalent phosphotyrosine linkage."; RL Biochemistry 45:5775-5782(2006). RN [7] RP FUNCTION. RX PubMed=20187656; DOI=10.1021/bi902204v; RA Stahley M.R., Stivers J.T.; RT "Mechanism and specificity of DNA strand exchange catalyzed by vaccinia DNA RT topoisomerase type I."; RL Biochemistry 49:2786-2795(2010). RN [8] RP X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS) OF 1-77. RX PubMed=7994576; DOI=10.1016/s0969-2126(94)00077-8; RA Sharma A., Hanai R., Mondragon A.; RT "Crystal structure of the amino-terminal fragment of vaccinia virus DNA RT topoisomerase I at 1.6-A resolution."; RL Structure 2:767-777(1994). RN [9] RP X-RAY CRYSTALLOGRAPHY (2.3 ANGSTROMS) OF 81-314. RX PubMed=9529259; DOI=10.1016/s0092-8674(00)81411-7; RA Cheng C., Kussie P., Pavletich N., Shuman S.; RT "Conservation of structure and mechanism between eukaryotic topoisomerase I RT and site-specific recombinases."; RL Cell 92:841-850(1998). 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 the specific target site CC 5'-[CT]CCTTp site in duplex DNA. The scissile phosphodiester is CC attacked by the catalytic tyrosine of the enzyme, resulting in the CC formation of a DNA-(3'-phosphotyrosyl)-enzyme intermediate and the CC expulsion of a 5'-OH DNA strand. The free DNA strand then undergoes CC passage around the unbroken strand thus removing DNA supercoils. CC Finally, in the religation step, the DNA 5'-OH attacks the covalent CC intermediate to expel the active-site tyrosine and restore the DNA CC phosphodiester backbone. {ECO:0000269|PubMed:16669621, CC ECO:0000269|PubMed:20187656}. 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 -!- SUBCELLULAR LOCATION: Virion {ECO:0000305}. CC -!- INDUCTION: Expressed in the late phase of the viral replicative cycle. 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; M13209; AAB59842.1; -; Genomic_DNA. DR EMBL; L13447; AAA02841.1; -; Unassigned_DNA. DR EMBL; AY243312; AAO89383.1; -; Genomic_DNA. DR PIR; G24481; QQVZH7. DR RefSeq; YP_232986.1; NC_006998.1. DR PDB; 1A41; X-ray; 2.30 A; A=81-314. DR PDB; 1VCC; X-ray; 1.60 A; A=1-77. DR AlphaFoldDB; P68698; -. DR MDposit; P68698; -. DR SMR; P68698; -. DR DNASU; 3707560; -. DR GeneID; 3707560; -. DR KEGG; vg:3707560; -. DR BRENDA; 5.6.2.1; 908. DR EvolutionaryTrace; P68698; -. DR PRO; PR:P68698; -. DR Proteomes; UP000000344; Segment. 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; IEA:UniProtKB-EC. DR GO; GO:0006265; P:DNA topological change; IEA:InterPro. DR CDD; cd00659; Topo_IB_C; 1. DR Gene3D; 3.30.66.10; DNA topoisomerase I domain; 1. DR Gene3D; 3.90.15.10; Topoisomerase I, Chain A, domain 3; 1. DR InterPro; IPR011010; DNA_brk_join_enz. DR InterPro; IPR035447; DNA_topo_I_N_sf. DR InterPro; IPR001631; TopoI. DR InterPro; IPR014711; TopoI_cat_a-hlx-sub_euk. DR InterPro; IPR013500; TopoI_cat_euk. DR InterPro; IPR015346; TopoI_N_vir. DR InterPro; IPR018521; TopoIB_AS. DR Pfam; PF01028; Topoisom_I; 1. DR Pfam; PF09266; VirDNA-topo-I_N; 1. DR PRINTS; PR00416; EUTPISMRASEI. DR SUPFAM; SSF56349; DNA breaking-rejoining enzymes; 1. DR SUPFAM; SSF55869; DNA topoisomerase I domain; 1. DR PROSITE; PS00176; TOPO_IB_1; 1. DR PROSITE; PS52038; TOPO_IB_2; 1. PE 1: Evidence at protein level; KW 3D-structure; Direct protein sequencing; DNA-binding; Isomerase; KW Late protein; Reference proteome; Topoisomerase; Virion. FT CHAIN 1..314 FT /note="DNA topoisomerase 1B" FT /id="PRO_0000145216" FT DOMAIN 77..314 FT /note="Topo IB-type catalytic" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01382" FT ACT_SITE 274 FT /note="O-(3'-phospho-DNA)-tyrosine intermediate" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01382, FT ECO:0000255|PROSITE-ProRule:PRU10130, FT ECO:0000269|PubMed:15755148" FT SITE 168 FT /note="Involved in religation" FT /evidence="ECO:0000250|UniProtKB:P32989" FT MUTAGEN 216 FT /note="G->E,K: No change in activity." FT /evidence="ECO:0000269|PubMed:8393454" FT MUTAGEN 217 FT /note="I->P: Temperature-sensitive for DNA relaxation in FT vitro." FT /evidence="ECO:0000269|PubMed:8393454" FT MUTAGEN 220 FT /note="K->D: Loss of activity." FT /evidence="ECO:0000269|PubMed:8393454" FT MUTAGEN 220 FT /note="K->I,N: Reduced activity." FT /evidence="ECO:0000269|PubMed:8393454" FT MUTAGEN 223 FT /note="R->E,G: Loss of activity." FT /evidence="ECO:0000269|PubMed:8393454" FT MUTAGEN 223 FT /note="R->K: Reduced activity." FT /evidence="ECO:0000269|PubMed:8393454" FT MUTAGEN 224 FT /note="T->G,P: Reduced activity." FT /evidence="ECO:0000269|PubMed:8393454" FT MUTAGEN 225 FT /note="Y->H: No change in activity." FT /evidence="ECO:0000269|PubMed:8393454" FT MUTAGEN 225 FT /note="Y->R,S: Reduced activity." FT /evidence="ECO:0000269|PubMed:8393454" FT MUTAGEN 274 FT /note="Y->F: Complete loss of activity." FT /evidence="ECO:0000269|PubMed:15755148" FT STRAND 3..7 FT /evidence="ECO:0007829|PDB:1VCC" FT STRAND 10..14 FT /evidence="ECO:0007829|PDB:1VCC" FT HELIX 27..33 FT /evidence="ECO:0007829|PDB:1VCC" FT HELIX 35..37 FT /evidence="ECO:0007829|PDB:1VCC" FT STRAND 41..46 FT /evidence="ECO:0007829|PDB:1VCC" FT HELIX 50..53 FT /evidence="ECO:0007829|PDB:1VCC" FT STRAND 56..62 FT /evidence="ECO:0007829|PDB:1VCC" FT STRAND 68..72 FT /evidence="ECO:0007829|PDB:1VCC" FT HELIX 82..105 FT /evidence="ECO:0007829|PDB:1A41" FT TURN 109..111 FT /evidence="ECO:0007829|PDB:1A41" FT HELIX 115..125 FT /evidence="ECO:0007829|PDB:1A41" FT HELIX 140..146 FT /evidence="ECO:0007829|PDB:1A41" FT HELIX 150..152 FT /evidence="ECO:0007829|PDB:1A41" FT STRAND 153..156 FT /evidence="ECO:0007829|PDB:1A41" FT STRAND 159..162 FT /evidence="ECO:0007829|PDB:1A41" FT STRAND 164..166 FT /evidence="ECO:0007829|PDB:1A41" FT TURN 167..169 FT /evidence="ECO:0007829|PDB:1A41" FT STRAND 170..172 FT /evidence="ECO:0007829|PDB:1A41" FT STRAND 175..178 FT /evidence="ECO:0007829|PDB:1A41" FT STRAND 180..182 FT /evidence="ECO:0007829|PDB:1A41" FT HELIX 183..189 FT /evidence="ECO:0007829|PDB:1A41" FT STRAND 197..200 FT /evidence="ECO:0007829|PDB:1A41" FT HELIX 205..214 FT /evidence="ECO:0007829|PDB:1A41" FT HELIX 219..241 FT /evidence="ECO:0007829|PDB:1A41" FT STRAND 242..244 FT /evidence="ECO:0007829|PDB:1A41" FT HELIX 248..263 FT /evidence="ECO:0007829|PDB:1A41" FT HELIX 266..268 FT /evidence="ECO:0007829|PDB:1A41" FT HELIX 269..282 FT /evidence="ECO:0007829|PDB:1A41" FT HELIX 288..292 FT /evidence="ECO:0007829|PDB:1A41" FT HELIX 297..309 FT /evidence="ECO:0007829|PDB:1A41" SQ SEQUENCE 314 AA; 36666 MW; E76FBCFCBF259D27 CRC64; MRALFYKDGK LFTDNNFLNP VSDDNPAYEV LQHVKIPTHL TDVVVYEQTW EEALTRLIFV GSDSKGRRQY FYGKMHVQNR NAKRDRIFVR VYNVMKRINC FINKNIKKSS TDSNYQLAVF MLMETMFFIR FGKMKYLKEN ETVGLLTLKN KHIEISPDEI VIKFVGKDKV SHEFVVHKSN RLYKPLLKLT DDSSPEEFLF NKLSERKVYE CIKQFGIRIK DLRTYGVNYT FLYNFWTNVK SISPLPSPKK LIALTIKQTA EVVGHTPSIS KRAYMATTIL EMVKDKNFLD VVSKTTFDEF LSIVVDHVKS STDG //