Kap114 and Nap1 ₂ co-chaperone H2A-H2B in the absence of Ran ^GTP . (A) Left, top to bottom: Structures of the nucleosome (1ID3), Nap1₂•H2A-H2B (5G2E), Kap114•H2A-H2B (8F0X), and Nap1₂•H2A-H2B•Kap114. Right panels, top to bottom: three views of the semi-transparent H2A-H2B surface with cartoon representation underneath, for the corresponding structures in the left panel. Binding interfaces (PDBePISA) are colored according to binding partners. Ovals highlight the H2B α1 helix, which is buried by Nap1₂ in Nap1₂•H2A-H2B and by Kap114 in Kap114•H2A-H2B, and very likely restricted in access by Nap1₂ in Nap1₂•H2A-H2B•Kap114. (B) DNA competition assays of DNA•H2A-H2B complex (D•H) added to Nap1 (N₂), Kap114 (K), or Kap114+Nap1₂ mixture (K+N₂), in the absence of Ran^GTP. Summary of DNA competition assay results as shown below. Samples were visualized using ethidium bromide- and Coomassie-stained native PAGE gels. (C) Similar assay as in B, but all proteins were assembled in complexes before the addition of DNA. Source data are available for this figure: SourceData F4.