P68697 (TOP1_VACCC) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
DNA topoisomerase 1B
Short name=TopIB
EC=5.99.1.2

Alternative name(s):
DNA topoisomerase I
Late protein H6

Gene names

Name:	TOP1
ORF Names:	H6R

Organism

Vaccinia virus (strain Copenhagen) (VACV) [Complete proteome]

Taxonomic identifier

10249 [NCBI]

Taxonomic lineage

Viruses › dsDNA viruses, no RNA stage › Poxviridae › Chordopoxvirinae › Orthopoxvirus › Vaccinia virus

Virus host

Homo sapiens (Human) [TaxID: 9606]

Protein attributes

Sequence length	314 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 the specific target site 5'-[CT]CCTTp 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.
Induction	Expressed in the late phase of the viral replicative cycle.
Sequence similarities	Belongs to the type IB topoisomerase family.

Ontologies

Keywords
Developmental stage	Late protein
Ligand	ATP-binding DNA-binding Nucleotide-binding
Molecular function	Isomerase Topoisomerase
Technical term	Complete proteome
Gene Ontology (GO)
Biological process	DNA topological change Inferred from electronic annotation. Source: InterPro
Cellular component	chromosome Inferred from electronic annotation. Source: InterPro
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 – 314	314	DNA topoisomerase 1B		PRO_0000145215
Sites
	Active site	274	1	O-(3'-phospho-DNA)-tyrosine intermediate By similarity
	Site	168	1	Involved in religation By similarity

Sequences

	Sequence		Length	Mass (Da)
	P68697 [UniParc]. Last modified August 1, 1988. Version 1. Checksum: E76FBCFCBF259D27	FASTA	314	36,666
	10 20 30 40 50 60 MRALFYKDGK LFTDNNFLNP VSDDNPAYEV LQHVKIPTHL TDVVVYEQTW EEALTRLIFV 70 80 90 100 110 120 GSDSKGRRQY FYGKMHVQNR NAKRDRIFVR VYNVMKRINC FINKNIKKSS TDSNYQLAVF 130 140 150 160 170 180 MLMETMFFIR FGKMKYLKEN ETVGLLTLKN KHIEISPDEI VIKFVGKDKV SHEFVVHKSN 190 200 210 220 230 240 RLYKPLLKLT DDSSPEEFLF NKLSERKVYE CIKQFGIRIK DLRTYGVNYT FLYNFWTNVK 250 260 270 280 290 300 SISPLPSPKK LIALTIKQTA EVVGHTPSIS KRAYMATTIL EMVKDKNFLD VVSKTTFDEF 310 LSIVVDHVKS STDG

References

[1]	"The complete DNA sequence of vaccinia virus." Goebel S.J., Johnson G.P., Perkus M.E., Davis S.W., Winslow J.P., Paoletti E. Virology 179:247-266(1990) [PubMed: 2219722] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[2]	"Appendix to 'The complete DNA sequence of vaccinia virus'." Goebel S.J., Johnson G.P., Perkus M.E., Davis S.W., Winslow J.P., Paoletti E. Virology 179:517-563(1990) Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	M35027 Genomic DNA. Translation: AAA48093.1.
PIR	QQVZH7. G24481.
3D structure databases
ProteinModelPortal	P68697.
SMR	P68697. Positions 1-314.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
InterPro	IPR011010. DNA_brk_join_enz. IPR018521. TopoI_AS. IPR001631. TopoI_C. IPR014711. TopoI_cat_a-hlx-sub_euk. IPR013500. TopoI_cat_euk. IPR015346. TopoI_N_vir. [Graphical view]
Gene3D	G3DSA:3.30.66.10. G3DSA:3.30.66.10. 1 hit. G3DSA:3.90.15.10. TopoI_cat_a-hlx-sub_euk. 1 hit.
Pfam	PF01028. Topoisom_I. 1 hit. PF09266. VirDNA-topo-I_N. 1 hit. [Graphical view]
PRINTS	PR00416. EUTPISMRASEI.
SUPFAM	SSF56349. DNA_brk_join_enz. 1 hit.
PROSITE	PS00176. TOPOISOMERASE_I_EUK. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

TOP1_VACCC

Accession

Primary (citable) accession number: P68697
Secondary accession number(s): P08585

Entry history

Integrated into UniProtKB/Swiss-Prot:	August 1, 1988
Last sequence update:	August 1, 1988
Last modified:	November 16, 2011
This is version 36 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Viral Protein Annotation Program