NAP1-Related Protein 1 (NRP1) has multiple interaction modes for chaperoning histones H2A-H2B

Proc Natl Acad Sci U S A. 2020 Dec 1;117(48):30391-30399. doi: 10.1073/pnas.2011089117. Epub 2020 Nov 16.

Abstract

Nucleosome Assembly Protein 1 (NAP1) family proteins are evolutionarily conserved histone chaperones that play important roles in diverse biological processes. In this study, we determined the crystal structure of Arabidopsis NAP1-Related Protein 1 (NRP1) complexed with H2A-H2B and uncovered a previously unknown interaction mechanism in histone chaperoning. Both in vitro binding and in vivo plant rescue assays proved that interaction mediated by the N-terminal α-helix (αN) domain is essential for NRP1 function. In addition, the C-terminal acidic domain (CTAD) of NRP1 binds to H2A-H2B through a conserved mode similar to other histone chaperones. We further extended previous knowledge of the NAP1-conserved earmuff domain by mapping the amino acids of NRP1 involved in association with H2A-H2B. Finally, we showed that H2A-H2B interactions mediated by αN, earmuff, and CTAD domains are all required for the effective chaperone activity of NRP1. Collectively, our results reveal multiple interaction modes of a NAP1 family histone chaperone and shed light on how histone chaperones shield H2A-H2B from nonspecific interaction with DNA.

Keywords: H2A-H2B; NAP1 family protein; crystal structure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Amino Acids
  • Arabidopsis
  • Binding Sites
  • Conserved Sequence
  • Crystallography, X-Ray
  • Histones / chemistry*
  • Histones / metabolism
  • Models, Molecular*
  • Nucleosome Assembly Protein 1 / chemistry*
  • Nucleosome Assembly Protein 1 / metabolism
  • Protein Binding
  • Protein Conformation
  • Protein Interaction Domains and Motifs

Substances

  • Amino Acids
  • Histones
  • Nucleosome Assembly Protein 1