Diversity and Functions of Type II Topoisomerases

The DNA double helix provides a simple and elegant way to store and copy genetic information. However, the processes requiring the DNA helix strands separation, such as transcription and replication, induce a topological side-effect ? supercoiling of the molecule. Topoisomerases comprise a specific group of enzymes that disentangle the topological challenges associated with DNA supercoiling. They relax DNA supercoils and resolve catenanes and knots. Here, we review the catalytic cycles, evolution, diversity, and functional roles of type II topoisomerases in organisms from all domains of life, as well as viruses and other mobile genetic elements. KEYWORDS topoisomerases, supercoiling, decatenation, transcription, replication, DNA segregation, spatial chromosome organization. ABBREVIATIONS LUCA ? last universal common ancestor; CTD ? C-terminal domain; TAD ? topologically associating domain; kb ? kilobase. The DNA double helix provides a simple and elegant way to store and copy genetic information. However, the processes requiring the DNA helix strands separation, such as transcription and replication, induce a topological side-effect ? supercoiling of the molecule. Topoisomerases comprise a specific group of enzymes that disentangle the topological challenges associated with DNA supercoiling. They relax DNA supercoils and resolve catenanes and knots. Here, we review the catalytic cycles, evolution, diversity, and functional roles of type II topoisomerases in organisms from all domains of life, as well as viruses and other mobile genetic elements.

Automated summary

The DNA double helix is a simple and elegant way to store and copy genetic information, but processes like transcription and replication can lead to a topological side effect of supercoiling. Topoisomerases are enzymes that help untangle the topological challenges associated with DNA supercoiling by relaxing supercoils and resolving catenanes and knots.