On the road from Histones to Chromosome

Eukaryotes and prokaryotes are the two superkingdoms of organisms. Eukaryotic chromosome is uninemic—that is contains one double helix of DNA. The DNA must be available for the preinitiation complex to formwith its RNA polymerase and general transcription factors.It appears that DNA wrapped around nucleosomes is often not accessible for the formation of the preinitiation complex but is available for recognition by transcription activating proteins also called specific transcription factors.We concentrate on the roles of histones their regulation and chromatin remodeling in gene expression.