A0A380G4F0 · A0A380G4F0_STAIN

Function

function

Releases the supercoiling and torsional tension of DNA, which is 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 a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(5'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 3'-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 3'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone.

Caution

Lacks conserved residue(s) required for the propagation of feature annotation.

Catalytic activity

  • ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.
    EC:5.6.2.1 (UniProtKB | ENZYME | Rhea)

Cofactor

Mg2+ (UniProtKB | Rhea| CHEBI:18420 )

Features

Showing features for binding site, site, active site.

TypeIDPosition(s)Description
Binding site9Mg2+ (UniProtKB | ChEBI); catalytic
Site61Interaction with DNA
Binding site105Mg2+ (UniProtKB | ChEBI); catalytic
Site168Interaction with DNA
Site176Interaction with DNA
Active site306O-(5'-phospho-DNA)-tyrosine intermediate
Site308Interaction with DNA

GO annotations

AspectTerm
Molecular FunctionDNA binding
Molecular FunctionDNA topoisomerase type I (single strand cut, ATP-independent) activity
Molecular Functionmagnesium ion binding
Biological ProcessDNA topological change

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    DNA topoisomerase 3
  • EC number
  • Alternative names
    • DNA topoisomerase III

Gene names

    • Name
      topB
    • ORF names
      NCTC11048_01006

Organism names

Accessions

  • Primary accession
    A0A380G4F0

Proteomes

Interaction

Protein-protein interaction databases

Family & Domains

Features

Showing features for domain, region.

TypeIDPosition(s)Description
Domain3-136Toprim
Region187-192Interaction with DNA

Sequence similarities

Belongs to the type IA topoisomerase family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    711
  • Mass (Da)
    81,786
  • Last updated
    2018-11-07 v1
  • Checksum
    AC033F31CB41CD91
MSKALILAEKPSVGRDIANALNIGSRKEGYFENQQYIVTWALGHLVTNATPEQYDKKYQQWVLEDLPIIPKQMKSVVIGKTRKQFNTVQHLMKRSDVNELIIATDAGREGELVARLIIEKAHVKKPIKRLWISSVTPKAIKEGFKKLKDGRAYDHLYQAALARSEADWIVGINATRALTTKYDAQLSLGRVQTPTIQLVAMRQEQIKNFKPQQYYTLEAEVNGVTMTYQHEGRIYHKEKLEAIVQELQHQHAQVNNVHEKEKKVYPQPLFNLTDLQQAAYQKYHLGAKQTLNTLQQLYERHKLVTYPRTDSNYLTTDMVDTLKERVQATMGTDLMPYAREILQQPFAKKLSFVNNQKVSDHHAIIPTEVRANIETLSPNERKIYTMIAQRYLEVLMPPYRYRAQHVEVRIGKHTFTYQSQVPVELGFKKLQQDRAQTERAVSFNQGETFEIGRLQIVAHETTPPAYFNEGTLLKAMERPDKFFDLKDKKSAQTLKTIGGIGTVATRADIIDKLFNMNAIESQDGKIKVTSKGKQILDLAPPALTSPRLTAEWEDKLMQIEKGQFKAQQFMQEMKKFTHEIINTIKSSEQKYKHDNLTSAQCPTCGKFMLKVNTKNGSMLVCQDPSCKTKKDVKTKTNARCPQCKKRLTKFGTGKKATYRCVCGYTETQEHMDQRFKNKGKDKVSKREMKKYMKEDELENNPFKDALKGLNL

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
UHDP01000003
EMBL· GenBank· DDBJ
SUM46014.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
FeedbackHelp