DNA topoisomerase I, mitochondrial; TOP1mt (TOP1MT)

Function

• relieves DNA strain that arises during duplication of mitochondrial DNA
• ATP-independent breakage of single-stranded DNA, followed by passage & rejoining

Cofactor: divalent metal ions (Ca+2 or Mg+2)

Structure

• belongs to the eukaryotic type 1 topoisomerase family

Compartment

mitochondria

Expression

• ubiquitous
• highest in skeletal muscle, heart, brain & fetal liver

Notes

• when a topoisomerase transiently breaks a DNA backbone bond, it simultaneously forms a protein-DNA link, in which a Tyr-oxygen in the enzyme is joined to a DNA phosphorus at one end of the enzyme-severed DNA strand

More general terms

• topoisomerase
• mitochondrial protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=116447
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:116447
• OMIM: https://mirror.omim.org/entry/606387
• UniProt: http://www.uniprot.org/uniprot/Q969P6.html