DNA topoisomerase type II (Topo II)

DNA topoisomerase type II (Topo II) is a dimeric enzyme that manages DNA topology by creating transient double-stranded DNA breaks, passing another DNA duplex (T-segment) through the break in the gate-segment (G-segment), and religating the break in an ATP-dependent manner. It features an N-terminal GHKL ATPase domain, a Toprim domain for Mg2+-dependent cleavage, a central DNA-binding core forming a heart-shaped structure with N-gate, DNA-gate, and C-gate interfaces, and a variable C-terminal domain. The enzyme undergoes conformational changes, including ATPase domain dimerization upon ATP binding, domain swapping, and a lysine-rich loop interaction with bent G-segment DNA to couple DNA binding to ATP hydrolysis, ensuring unidirectional strand passage for processes like replication, transcription, chromosome segregation, and supercoil relaxation.[1][2][3][4]

Other names

Type IIA topoisomeraseType II DNA topoisomeraseTopoisomerase II