Q8T2T7 · TOP3_DICDI

Function

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 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 than 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 (By similarity).

Catalytic activity

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

Features

Showing features for active site.

1828100200300400500600700800
TypeIDPosition(s)Description
Active site361O-(5'-phospho-DNA)-tyrosine intermediate

GO annotations

AspectTerm
Cellular Componentnucleus
Cellular ComponentRecQ family helicase-topoisomerase III complex
Molecular FunctionDNA binding
Molecular FunctionDNA topoisomerase type I (single strand cut, ATP-independent) activity
Biological ProcessDNA recombination
Biological ProcessDNA repair
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
      top3
    • ORF names
      DDB_G0275257

Organism names

Accessions

  • Primary accession
    Q8T2T7
  • Secondary accessions
    • Q554F7

Proteomes

Organism-specific databases

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00003304801-828DNA topoisomerase 3

Proteomic databases

Interaction

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for domain, region.

Type
IDPosition(s)Description
Domain4-149Toprim
Domain167-617Topo IA-type catalytic
Region763-828Disordered

Sequence similarities

Belongs to the type IA topoisomerase family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    828
  • Mass (Da)
    94,639
  • Last updated
    2002-06-01 v1
  • MD5 Checksum
    DD1B086DA95DBA250BA61EC79403A653
MTKRILNVAEKPSAAKEIAAILSNKRATVREGFSKYNKLWDFKYNILNFNDCEMTFTSVTGHLMEIDVVEQFKPWASCDPIQLFDAPIRKTVPSDKEPLKKTLEREIKKADILILWLDCDREGENIAFEVLEVCKNAKKKFEFYRAHFSAIIPREIDRACKNLAKPNEKDSIAVDTRMEIDLRIGAAFTRFQTLYLKKFKIISNSDNQPKTTTPANGNILNNSNNNSSGKEIISYGPCQFPTLGFVVERYFRIVNFKPEDFWHLSVVHEKMDTSSGKMIPVTFSWCRNRLFDYTAAFILYEKCLDNTEATVVDVTSKESRYRPVPLTTIELQKAASKKLRISSVQTMQYAEELYTKGLISYPRTETDSFQAGTDLKGLIGNQASNPEWGAYASRLINNNQFVYPKSGKNNDNSHPPIHPTSSATGLSGNLKKIYDFITRRFLACCSEESVFANTTVTIDIQGERFSETGTMVLKLGYLEVYPFDKRNDKLIPTYQKGERFTPKRIDLTKGTTVAPHYITEAELLTAMDNNKIGTDATMATHIQTIQDRFYVKKNESNQFVPSNLGVSLVASYELMGFEFSKPNLRAAIEADVDKISRGQKTKQEVLLSTIEKYKQLYQLANQNINCFDRSFREYYEPADPKGGEFRVLVSQFSRCGKCNGKMQYKSDQNPEAPKRILFCPQCIDTFDLPKNGDISQLVTSMGVPQNCPICQYQVLSVRNPINDKSYTICPKCRNSPPDPIHKKPFHCFQCTFNCNLATGNKQQQQQQQQQQQQTNYNRNNNNNNTNSARPITTRTTRTTTQHRTFTASNNNFNNNNRNSDRNNNNFIF

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AAFI02000013
EMBL· GenBank· DDBJ
EAL69909.2
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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