Multiple sites of the nucleosome-positioning are associated with the matrix associated regions (MARs/SARs)

Maps of nucleosome-positioning sites for sequences of more than 20 matrix associated regions published previously have been constructed. Comparison of the maps with localization of context characteristics (purine-pyrimidine tracts, ATG-, ATC-sequences, repeats of the T$_{1\text-5}$G$_{1\text-5}$, C$_{1\text-5}$A$_{1\text-5}$ motives, TG, CA,TA dinucleotide repeats, motives of telomeric repeats, AT-rich sequences, sites of TopoII isomerase) has been executed. It became evident that matrix associated regions longer than 800 bp incorporate numerous strong sites of nucleosome-positioning, which are often consecutive. Usually these zones abut on low-potential regions. The latter are associated with increasing occurrence of context characteristics or the length in the case of tracts. The exception to the rule among the sets presented is the example of the intron of beta-globine gene (Homo sapiens). It incorporates strong MARs, some context characteristics, but strong nucleosome-positioning sites are not located in the vicinity.