UniProt functional annotation for P32989



	UniProt functional annotation for P32989

UniProt code: P32989.

Organism: Variola virus (isolate Human/India/Ind3/1967) (VARV) (Smallpox virus).

Taxonomy: Viruses; Varidnaviria; Bamfordvirae; Nucleocytoviricota; Pokkesviricetes; Chitovirales; Poxviridae; Chordopoxvirinae; Orthopoxvirus.

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 then 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). {ECO:0000250}.

Catalytic activity: Reaction=ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.; EC=5.6.2.1; Evidence={ECO:0000255|PROSITE- ProRule:PRU10130};

Induction: Expressed in the late phase of the viral replicative cycle.

Similarity: Belongs to the type IB topoisomerase family. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.


Organism:		Variola virus (isolate Human/India/Ind3/1967) (VARV) (Smallpox virus).
Taxonomy:		Viruses; Varidnaviria; Bamfordvirae; Nucleocytoviricota; Pokkesviricetes; Chitovirales; Poxviridae; Chordopoxvirinae; Orthopoxvirus.



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 then 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). {ECO:0000250}.


Catalytic activity:		Reaction=ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.; EC=5.6.2.1; Evidence={ECO:0000255\|PROSITE- ProRule:PRU10130};
Induction:		Expressed in the late phase of the viral replicative cycle.
Similarity:		Belongs to the type IB topoisomerase family. {ECO:0000305}.