Structure and functional relationships of archaeal and eukaryal histones and nucleosomes

Abstract

A decade after the discovery of histones in Archaea, there is now also a biochemical description of the archaeal nucleosome. A tetrameric core of archaeal histones is encircled by ~80 bp of DNA, and nuclease digestions indicate that adjacent archaeal nucleosomes exist in vivo compacting archaeal genomic DNA. Most Eukarya employ a similar structure to organize their chromosomal DNA, the eukaryal nucleosome, with a histone octamer and 146 bp of DNA. Here we compare the properties of both nucleosomes in terms of DNA packaging and the accessibility of the packaged DNA for transcription.