UniProt Summary: 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). Possesses negatively supercoiled DNA relaxing activity. {ECO:0000250}.
Pfam DomainsGO Terms
Pfam Domains
Topoisom bac
Toprim
GO Terms
DNA topoisomerase activity
DNA topoisomerase type I activity
DNA topological change
condensed chromosome
chromosome segregation
DNA conformation change
DNA metabolic process
chromosome organization
RNA binding
DNA binding
CRISPR Data
Compound HitMost Correlated Genes in ChemogenomicsTissues where Essential in the Avana Dataset (DepMap 20Q1)
Compound Hit
No hits were found.
Most Correlated Genes in Chemogenomics
No correlation found to any other genes in chemogenomics.
Tissues where Essential in the Avana Dataset (DepMap 20Q1)
Global Fraction of Cell Lines Where Essential: 0/739