External Ids for TOP1MT Gene
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. [provided by RefSeq, May 2012]
GeneCards Summary for TOP1MT Gene
TOP1MT (Topoisomerase (DNA) I, Mitochondrial) is a Protein Coding gene. GO annotations related to this gene include DNA topoisomerase type I activity and DNA topoisomerase type II (ATP-hydrolyzing) activity. An important paralog of this gene is TOP1.
UniProtKB/Swiss-Prot for TOP1MT Gene
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).