Structural basis for allosteric regulation of Human Topoisomerase IIα

Nat Commun. 2021 May 20;12(1):2962. doi: 10.1038/s41467-021-23136-6.

Abstract

The human type IIA topoisomerases (Top2) are essential enzymes that regulate DNA topology and chromosome organization. The Topo IIα isoform is a prime target for antineoplastic compounds used in cancer therapy that form ternary cleavage complexes with the DNA. Despite extensive studies, structural information on this large dimeric assembly is limited to the catalytic domains, hindering the exploration of allosteric mechanism governing the enzyme activities and the contribution of its non-conserved C-terminal domain (CTD). Herein we present cryo-EM structures of the entire human Topo IIα nucleoprotein complex in different conformations solved at subnanometer resolutions (3.6-7.4 Å). Our data unveils the molecular determinants that fine tune the allosteric connections between the ATPase domain and the DNA binding/cleavage domain. Strikingly, the reconstruction of the DNA-binding/cleavage domain uncovers a linker leading to the CTD, which plays a critical role in modulating the enzyme's activities and opens perspective for the analysis of post-translational modifications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allosteric Regulation
  • Animals
  • Catalytic Domain
  • Cell Line
  • Cryoelectron Microscopy
  • DNA / metabolism
  • DNA / ultrastructure
  • DNA Topoisomerases, Type II / genetics
  • DNA Topoisomerases, Type II / isolation & purification
  • DNA Topoisomerases, Type II / metabolism
  • DNA Topoisomerases, Type II / ultrastructure*
  • Humans
  • Mesocricetus
  • Models, Molecular
  • Nucleoproteins
  • Poly-ADP-Ribose Binding Proteins / genetics
  • Poly-ADP-Ribose Binding Proteins / isolation & purification
  • Poly-ADP-Ribose Binding Proteins / metabolism
  • Poly-ADP-Ribose Binding Proteins / ultrastructure*
  • Protein Processing, Post-Translational
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Recombinant Proteins / ultrastructure

Substances

  • Nucleoproteins
  • Poly-ADP-Ribose Binding Proteins
  • Recombinant Proteins
  • DNA
  • DNA Topoisomerases, Type II
  • TOP2A protein, human