Topoisomerase 2, also known as DNA topoisomerase II, is an enzyme that plays a crucial role in DNA metabolism. Here are some key functions of topoisomerase 2: DNA Unwinding: Topoisomerase 2 is involved in the unwinding of DNA during processes like DNA replication and transcription. It helps relieve the torsional stress that builds up ahead of the replication fork or RNA polymerase by introducing temporary double-stranded breaks in the DNA. DNA Decatenation: Topoisomerase 2 is responsible for decatenating DNA, which refers to the separation of interlinked or intertwined DNA molecules. During DNA replication, sister chromatids are initially intertwined, and topoisomerase 2 resolves these interlinks to separate the replicated DNA molecules. Chromosome Condensation: Topoisomerase 2 plays a crucial role in the condensation of chromosomes during cell division. It helps to compact and organize DNA into the characteristic condensed structures seen during mitosis and meiosis. Regulation of DNA Topology: Topoisomerase 2 is involved in maintaining the proper topology of DNA by altering the number of twists and supercoils in the DNA molecule. It can introduce both negative and positive supercoils into the DNA, depending on the specific cellular context and requirements. Repair of DNA Damage: Topoisomerase 2 participates in DNA repair processes by resolving DNA knots and tangles that can occur due to DNA damage, such as DNA double-strand breaks. It helps in the proper rejoining of DNA strands and the restoration of the DNA structure. Overall, topoisomerase 2 plays essential roles in DNA replication, chromosome dynamics, and DNA repair, ensuring the proper functioning and integrity of the genome.