Histones, Archaea

However, the packing of DNA into nucleosome-like structures is not unique to eukarya similar structures appear in archaea (reviewed in Reeve et al., 1997). Additionally, histones and minichromosome maintenance proteins (MCM) are widespread among eukarya and archaea and absent in prokarya, and the eukaryotic chromo domain has a structure that is highly reminiscent of archaeal histones that are involved in formation of archaeal chromatin (Ball et al., 1997). Consequently, it is possible that chromatin remodeling in eukaryotes is an elaboration of a similar cellular mechanism in archaea. 

Still another clue seemed to be the discovery in Thermoplasma (a wall-less prokaryote ) of a histone, which was interpreted to mean that this organism represented the ancestry of eukaryotes [21]. Unfortunately, this clue turned out to be a false one, because the histone, upon later sequencing, proved to be of the bacterial, not the eukaryotic, type [22]. True or not, at the time this claim might have been reason to question the prokaryote concept. But, again, nothing of the sort happened - in this case perhaps because we had long been assured that the ancestor of eukaryotic cells was a prokaryote that had lost its cell wall [23]. It remained for Sandman et al. [24] to show, much later, that an eukaryotic type of histone does indeed exist in the archaea. 

Higashibata H, Fujiwara S, Ezaki S, Takagi M, Fukui K, Imanaka T (2000) Effect of polyamines on histone-induced DNA compaction of hyperthermophilic Archaea. J Biosci Bioeng 89 103-106 Hou MH, Lin SB, Yuann JM, Lin WC, Wang AH, Kan Ls L (2001) Effects of polyamines on the thermal stability and formation kinetics of DNA duplexes with abnormal structure. Nucleic Acids Res 29 5121-5128... 

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