Biopolymers and cell. 1987. Volume 3. № 5. 251 - 257

E. V. Kiseleva, E. V. Likhoshvay, A. B. Khrisiolyubova, N. V. Vorobyova, A'. A. Serdyukova, A. G. Roinashchcnko

ELECTRON-MICROSCOPIC STUDY OF THE STRUCTURE OF ROSETTE-LIKE NUCLEOPROTEID COMPLEXES ISOLATED FROM ESCHERICHIA COLI CELLS

Summary

    The structure of rosette-like DNA complexes is described in the material isolated by means of a mild technique from the bacterial cell lysate. DNAse treatment is shown to lead to ruptures in the rosettes' loops. Phospholipase and RNAse destroy the bonds between loops in the central region of rosettes, due to which the contour length of the loops increases considerably. Pronase induces a diminution of the diameter of central electron-dense globules, that leads to a gradual unfolding of roseltes to form the circular and loop-like structures. This evidences for participation of ribonucleoprotcins and, possibly, lipids in the formation of rosette-like DNA packing which may be connected with the functional organization of the prokaryotic genome.