Topoisomerase 3 refers to a family of type IA topoisomerases, which are enzymes that manage DNA topology by transiently breaking and rejoining single strands of DNA.
These enzymes are encoded by the TOP3A (topoisomerase III alpha) and TOP3B (topoisomerase III beta) genes.
Topoisomerase 3 enzymes relieve supercoiling and torsional stress in DNA during replication and transcription by passing one single strand through another, thus altering DNA topology.
They act as principal decatenases, unlinking daughter chromosomes after DNA replication, which is crucial for proper chromosome segregation.
TOP3A forms a complex with the BLM helicase to resolve recombination intermediates and prevent crossover events, maintaining genome stability.
Unlike TOP3A, TOP3B can act on both DNA and RNA, playing roles in R-loop disassembly and mRNA translation, with implications for neurodevelopment and disease.
Key Differences: TOP3A vs. TOP3B
Unlike TOP3А, TOP3B can act on both DNA and RNA, playing roles in R-loop disassembly and mRNA translation, with implications for neurodevelopment and disease.
Defects in topoisomerase 3 enzymes can lead to genome instability, cancer, and neurological disorders, highlighting their essential role in DNA and RNA metabolism.