image a
image b
Figure 2–17. A — elongated dividing cell of Proteus vulgaris on which the bright areas shown by figures are nucleoids (After Peshkov, 1955); B — chromatin bodies of Bacillus cereus (After Robinow, 1962; From Hayes, 1964).
It was until recently believed that in the formation of the bacterial
genome, in contrast to the chromosomes of eukaryotic cells, histones and
proteins of that kind do not take any part. This was even accepted as the
main distinction between the bacterial nucleoid and the nucleus of
eukaryotic cells. Now there are data available about the presence of
histone-like proteins in the prokaryote genome as well, that evidently
participate in the formation of structures resembling those of the
nucleosomes in eukaryotes (Rouvière-Yaniv, Gros, 1975, Rouvière-Yaniv
et al, 1979; Hübscher et al, 1980). Along with RNA they play a definite
stabilization role in the genome organization. In E. coli the approximately