Names & Taxonomy
- Uniprot ID:
- Q969P6
- Entry Name:
- TOP1M_HUMAN
- Status:
- reviewed
- Protein Names:
- DNA topoisomerase I, mitochondrial (TOP1mt) (EC 5.99.1.2)
- Gene Names:
- TOP1MT
- Gene Names Primary:
- TOP1MT
- Organism:
- Homo sapiens (Human)
Structure
- Length:
- 601
- Sequence:
- MRVVRLLRLRAALTLLGEVPRRPASRGVPGSRRTQKGSGARWEKEKHEDGVKWRQLEHKGPYFAPPYEPLPDGVRFFYEGRPVRLSVAAEEVATFYGRMLDHEYTTKEVFRKNFFNDWRKEMAVEEREVIKSLDKCDFTEIHRYFVDKAAARKVLSREEKQKLKEEAEKLQQEFGYCILDGHQEKIGNFKIEPPGLFRGRGDHPKMGMLKRRITPEDVVINCSRDSKIPEPPAGHQWKEVRSDNTVTWLAAWTESVQNSIKYIMLNPCSKLKGETAWQKFETARRLRGFVDEIRSQYRADWKSREMKTRQRAVALYFIDKLALRAGNEKEDGEAADTVGCCSLRVEHVQLHPEADGCQHVVEFDFLGKDCIRYYNRVPVEKPVYKNLQLFMENKDPRDDLFDRLTTTSLNKHLQELMDGLTAKVFRTYNASITLQEQLRALTRAEDSIAAKILSYNRANRVVAILCNHQRATPSTFEKSMQNLQTKIQAKKEQVAEARAELRRARAEHKAQGDGKSRSVLEKKRRLLEKLQEQLAQLSVQATDKEENKQVALGTSKLNYLDPRISIAWCKRFRVPVEKIYSKTQRERFAWALAMAGEDFEF
- Proteomes:
- UP000005640
Subcellular location
- Subcellular Location:
- Mitochondrion
Function
- Function:
- Releases the supercoiling and torsional tension of DNA introduced during duplication of mitochondrial DNA 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-(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).
- Catalytic Activity:
- ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.
- Cofactor:
- COFACTOR: Name=Ca(2+); Xref=ChEBI:CHEBI:29108;
- Active Site:
- ACT_SITE 559 559 O-(3'-phospho-DNA)-tyrosine intermediate.
- Cross Reference Drug Bank:
- DB00762 DB01030
- Gene Ontology Go:
- chromosome
mitochondrial nucleoid
mitochondrion
nucleus
DNA binding
DNA topoisomerase type I activity
DNA topoisomerase type II (ATP-hydrolyzing) activity
DNA replication
DNA topological change - Gene Ontology Biological Process:
- DNA replication
DNA topological change - Gene Ontology Molecular Function:
- DNA binding
DNA topoisomerase type I activity
DNA topoisomerase type II (ATP-hydrolyzing) activity - Gene Ontology Cellular Component:
- chromosome
mitochondrial nucleoid
mitochondrion
nucleus - Keywords:
- Alternative splicing
Complete proteome
DNA-binding
Isomerase
Mitochondrion
Polymorphism
Reference proteome
Topoisomerase
Transit peptide