Structure of histone-based chromatin in Archaea

• DOI: 10.1126/science.aaj1849
• Publication Date: 2017-08-28T19:10:39Z
• Authors: Francesca Mattiroli; Sudipta Bhattacha...; Pamela N. Dyer; Alison E. White; Kathleen Sandman; Brett W. Burkhart; Kyle R. Byrne; Thomas Lee; Natalie G. Ahn; Thomas J. Santangelo; John N. Reeve; Karolin Luger
• Keywords: Hyperthermophile; Histone code; Superhelix; Histone octamer

Small basic proteins present in most Archaea share a common ancestor with the eukaryotic core histones. We report crystal structure of an archaeal histone-DNA complex. DNA wraps around extended polymer, formed by histone homodimers, quasi-continuous superhelix same geometry as nucleosome. Substitutions conserved glycine at interface adjacent protein layers destabilize chromatin, reduce growth rate, and impair transcription regulation, confirming biological importance polymeric structure. Our data establish that histone-based mechanism compaction predates nucleosome, illuminating origin