7qfo
Human Topoisomerase II Beta ATPase AMPPNP
Structural highlights
FunctionTOP2B_HUMAN Control of topological states of DNA by transient breakage and subsequent rejoining of DNA strands. Topoisomerase II makes double-strand breaks. Indirectly involved in vitamin D-coupled transcription regulation via its association with the WINAC complex, a chromatin-remodeling complex recruited by vitamin D receptor (VDR), which is required for the ligand-bound VDR-mediated transrepression of the CYP27B1 gene.[1] [2] Publication Abstract from PubMedHuman topoisomerase II beta (TOP2B) modulates DNA topology using energy from ATP hydrolysis. To investigate the conformational changes that occur during ATP hydrolysis, we determined the X-ray crystallographic structures of the human TOP2B ATPase domain bound to AMPPNP or ADP at 1.9 A and 2.6 A resolution, respectively. The GHKL domains of both structures are similar, whereas the QTK loop within the transducer domain can move for product release. As TOP2B is the clinical target of bisdioxopiperazines, we also determined the structure of a TOP2B:ADP:ICRF193 complex to 2.3 A resolution and identified key drug-binding residues. Biochemical characterization revealed the N-terminal strap reduces the rate of ATP hydrolysis. Mutagenesis demonstrated residue E103 as essential for ATP hydrolysis in TOP2B. Our data provide fundamental insights into the tertiary structure of the human TOP2B ATPase domain and a potential regulatory mechanism for ATP hydrolysis. A comprehensive structural analysis of the ATPase domain of human DNA topoisomerase II beta bound to AMPPNP, ADP, and the bisdioxopiperazine, ICRF193.,Ling EM, Basle A, Cowell IG, van den Berg B, Blower TR, Austin CA Structure. 2022 Aug 4;30(8):1129-1145.e3. doi: 10.1016/j.str.2022.05.009. Epub , 2022 Jun 3. PMID:35660158[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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