Characterization of Caenorhabditis elegans Nucleosome Assembly Protein 1 Uncovers the Role of Acidic Tails in Histone Binding




Journal Title

Journal ISSN

Volume Title


Amer Chemical Soc


Nucleosome assembly proteins (Naps) influence chromatin dynamics by directly binding to histones. Here we provide a comprehensive structural and biochemical analysis of a Nap protein from Caenorhabditis elegans (CeNap1). CeNap1 naturally lacks the acidic N-terminal tail and has a short C-terminal tail compared to many other Nap proteins. Comparison of CeNap1 with full length and tail-less constructs of Saccharomyces cerevisiae Nap1 uncovers the role of these tails in self-association, histone binding, and Nap competition with DNA for H2A-H2B. We find that the presence of tails influences the stoichiometry of H2A-H2B binding and is required to complete the interactions between H2A-H2B and DNA. The absolute stoichiometry of the Nap protein and H2A-H2B complex is 2:1 or 2:2, with only a very small population of higher-order oligomers occurring at 150 mM NaCl. We also show that H3-H4 binds differently than H2A-H2B and that an (H3-H4)(2) tetramer can simultaneously bind two Nap₂ protein homodimers.


Due to copyright restrictions and/or publisher's policy full text access from Treasures at UT Dallas is limited to current UTD affiliates (use the provided Link to Article).
Supplementary material is available on publisher's website. Use the DOI link below.


Crystals, Structure, Interleukin-8, Nucleosomes, Chromatin, Caenorhabditis elegans


©2018 American Chemical Society