Open AccessControlling the topology of mammalian mitochondrial DNA
Author(s) -
Katja E. Menger,
Alejandro Rodríguez-Luis,
James Chapman,
Thomas J. Nicholls
Publication year - 2021
Publication title -
open biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.078
H-Index - 53
ISSN - 2046-2441
DOI - 10.1098/rsob.210168
Subject(s) - mitochondrial dna , dna supercoil , topoisomerase , biology , human mitochondrial genetics , mitochondrion , topology (electrical circuits) , genetics , dna , nucleoid , microbiology and biotechnology , dna replication , gene , mathematics , escherichia coli , combinatorics
The genome of mitochondria, called mtDNA, is a small circular DNA molecule present at thousands of copies per human cell. MtDNA is packaged into nucleoprotein complexes called nucleoids, and the density of mtDNA packaging affects mitochondrial gene expression. Genetic processes such as transcription, DNA replication and DNA packaging alter DNA topology, and these topological problems are solved by a family of enzymes called topoisomerases. Within mitochondria, topoisomerases are involved firstly in the regulation of mtDNA supercoiling and secondly in disentangling interlinked mtDNA molecules following mtDNA replication. The loss of mitochondrial topoisomerase activity leads to defects in mitochondrial function, and variants in the dual-localized type IA topoisomerase TOP3A have also been reported to cause human mitochondrial disease. We review the current knowledge on processes that alter mtDNA topology, how mtDNA topology is modulated by the action of topoisomerases, and the consequences of altered mtDNA topology for mitochondrial function and human health.