Biopolymers and cell. 1985. Volume 1. № 4. 179 - 182

V. D. Paponov

THE ROLE OF POLYANIONS AS DNA CONFORMONS AND COMPETITORS IN CHROMATIN ORGANIZATION

Summary

    Polyanionic components of cell nucleus participating in chromatin organization may be devided into two classes. The first class of permanent and transitive conformons provides specific conformations of DNA fragments and/or special states of corresponding sites of chromatin fibers for a long and short period of time, respectively. The second class of polyanions fulfils the role of competitors with DNA for the chromatin components. So-called «factors of chromatin assembly* occurring in some cells as complexes with molecules of nonchromosomal histone pool are representatives of the second class of the nuclear polyanions. The functional role of formation of the above complexes may be in prevention of histone competition for DNA, which causes in vitro the assembly or reor¬ganization of chromatin into the nucleoprotein completely devoid of the histone HI even at 1.5-2-fold weight excess of the whole histone over DNA.