Mechanism of AT base pairs recognition by molecules of dye "Hoechst 33258"
Mikhaĭlov, M.V.; Zasedatelev, A.S.; Krylov, A.S.; Gurskiĭ, G.V.
Molekuliarnaia Biologiia 15(3): 690-705
1981
ISSN/ISBN: 0026-8984 PMID: 6166855 Document Number: 174725
Experimental studies are reported on the binding of the dye "Hoechst 33 258" to DNA and synthetic polynucleotides. A stereochemical model of binding of the dye to DNA is proposed. According to the model, the molecules of the dye are located in the minor groove of DNA, each covering 4 base pairs. The benzimidazole backbone of the dye tends to form a helix isogeometric to that of DNA in the B form. The specifisity of "Hoechst 33 258" binding to At pairs involves hydrogen bonding of two NH-groups of benzimidazole rings and CH3N+H group of the piperazine ring to O2 oxygenes of thymines and N3 nitrogens of adenines facing the minor groove of the DNA double helix.