Electron microscopic studies of compactization of circular DNA in model systems. I. Compact structure of complexes of the synthetic peptide trivaline with circular DNA, containing a sequence, causing a stationary bend in DNA
Vengerov, I.I.; Martynkina, L.P.; Bespalov, M.M.; Strel'tsov, S.A.; Iurchenko, V.I.; Kolesnikov, A.A.
Molekuliarnaia Biologiia 31(2): 232-239
1997
ISSN/ISBN: 0026-8984 PMID: 9213750 Document Number: 471818
Electron microscopy was used to study the structure of complexes of synthetic peptide dansylhydrazide trivaline with a sequence that induced stationary DNA bending. Genetic engineering constructions pLg-19 and pTbo-1 created on the basis of vector pBluescript II KS+ were used. pLg-19 DNA contained a fragment of Leishmania gymnodactili minicircular DNA with a single stationarily bent region and pTbo-1 DNA contained four similar regions. The study of dansylhydrazide trivaline with such DNAs shows that the presence of bent DNA regions does not affect the final result of compactization with dansylhydrazide trivaline and that circular compact structures identical to triple rings described earlier for pBR322 DNA are formed. Nevertheless, some features were observed that could be associated with the presence of bent DNA regions. The study of the compact structures of high molecular weight circular DNAs showed that dimeric molecules pTho-1 with size of more than 12 thousand base pairs along with triple rings, contained structures with two or more circular regions joined together. The results of the study demonstrate the possible existence of independent compactization of individual regions of a single molecule induced by interaction with trivaline. Potential role of bent DNA regions in the formation of unusual compact structures is discussed.