Structural insights into H2A-H2B and H2A.Z-H2B sliding on histone chaperone NAP1

• Crystal structures reveal three new binding poses of H2A/H2A.Z-H2B on NAP1, expanding the known repertoire to five distinct poses. • H2A/H2A.Z-H2B can slide approximately 20.7 Å along the acidic surface of NAP1, suggesting a sliding mechanism for histone chaperone function. • The interaction is primarily mediated by salt bridges and electrostatic interactions between the acidic C-terminal tail of NAP1 and the basic αN-α1 region of H2A/H2A.Z. • These findings provide new mechanistic insights into nucleosome assembly and may inform therapeutic strategies targeting chromatin dynamics.