A0A1X9Z311 · A0A1X9Z311_9SPHI

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)

Features

Showing features for site, active site.

TypeIDPosition(s)Description
Site33Interaction with DNA
Site139Interaction with DNA
Site140Interaction with DNA
Site143Interaction with DNA
Site155Interaction with DNA
Active site285O-(5'-phospho-DNA)-tyrosine intermediate
Site287Interaction with DNA
Site477Interaction with DNA

GO annotations

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

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    DNA topoisomerase 1
  • EC number
  • Alternative names
    • DNA topoisomerase I

Gene names

    • Name
      topA
    • ORF names
      CA265_07115

Organism names

Accessions

  • Primary accession
    A0A1X9Z311

Proteomes

Interaction

Subunit

Monomer.

Family & Domains

Features

Showing features for domain, region, compositional bias.

TypeIDPosition(s)Description
Domain3-113Toprim
Region163-168Interaction with DNA
Region834-853Disordered
Compositional bias839-853Basic residues

Sequence similarities

Belongs to the type IA topoisomerase family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    853
  • Mass (Da)
    96,413
  • Last updated
    2017-08-30 v1
  • Checksum
    5F0006ECC1327D70
MAKNLLIVESPAKAKTIEGYLGKDFLVKSSYGHIRDLVKGDMAIDIKNNFAQTYEVPADKKNVVAELKKLAKEAEMVWLASDEDREGEAISWHLFETLGLKVEKTKRIVFHEITKPAILKAIESPRGIDYNLVNAQQARRVLDRLVGFELSPVLWKKVKPSLSAGRVQSVAVRLIVDREREVLNFNAAAAYKITAQFSTGKGRELVKAELPQRFENEADAEKFLQDCVNARFDITSLETRPAKRNPAAPFTTSTLQQEASRKLGFSVARTMQVAQRLYEAGKITYMRTDSVNLSETALNAAAAEIKSAYGDKYHQQRIYKTKSAGAQEAHEAIRPTYFDRHSVDGDISEKRLYDLIWKRSIASQMSEALFEKTTAQITASTRKEYLVAEGEVLKFDGFLKVYLESTDDEENEEKEGGAILPPLSKGQELFLKEMQATERYSRPPARYTEASLVKKLEELGIGRPSTYAPTISTVQNRGYVVKEDRDGKQRKFTSIILADGQVKKETKSEITGAEKSKLFPTDIGEVVNDFLVEHFKGIVDFNFTAKVEKEFDEIAQGLQEWTKMLHSFYNPFHTEVETTLETAERATGERLLGLDPATGKNVYTKVGKFGPLVQIGELDEEEKPRYASLMRTQSVATITLDDALELFKLPFQLPDFEGKEVMIGVGRFGPYVKWGESFISLPKNEEPLSVTYERAVEIIRQKMDDDAPIAYYEGLGVTKGKGRFGPFIKWNDLFINIPAKGYDFDNLTQEDINTLIGKKVEKEANRYIKTWDAEKISIENGRWGPFIRFGKLMLKLRNNEATKQKYTPEELVDIDLEVVKKMIVEQVPNAFETKKKAPAKKKAPAKKAVAKKK

Features

Showing features for compositional bias.

TypeIDPosition(s)Description
Compositional bias839-853Basic residues

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CP021237
EMBL· GenBank· DDBJ
ARS39432.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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