Recombinant Human DNA topoisomerase I, mitochondrial (TOP1MT)

Uniprot Id

Q969P6

Target Species

Human

Target Name

TOP1MT

Target Full Name

DNA topoisomerase I, mitochondrial

Target 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 rotates around the intact phosphodiester bond on the opposing 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.

Target Subcellular Location

Mitochondrion.

Target Protein Families

Type IB topoisomerase family

Target Tissue Specificity

Ubiquitous; highest in skeletal muscle, heart, brain and fetal liver.

Target Synonyms

TOP1MT; DNA topoisomerase I; mitochondrial; TOP1mt; EC 5.6.2.1

Target Background

This gene encodes a mitochondrial DNA topoisomerase that plays a role in the modification of DNA topology. The encoded protein is a type IB topoisomerase and catalyzes the transient breaking and rejoining of DNA to relieve tension and DNA supercoiling generated in the mitochondrial genome during replication and transcription. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene.