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Z‐DNA and other non‐B‐DNA structures are reversed to B‐DNA by interaction with netropsin
Author(s) -
Zimmer Christoph,
Marck Christian,
Guschlbauer Wilhelm
Publication year - 1983
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(83)80894-1
Subject(s) - z dna , circular dichroism , dna , chemistry , stereochemistry , netropsin , titration , crystallography , biochemistry , inorganic chemistry , minor groove
The interaction between the B‐form specific ligands netropsin (Nt) and distamycin‐3 (Dst‐3) and DNA duplexes has been studied under conditions of salt concentration and low water activity that modify the polymer conformation into a non‐B DNA form, putatively a Z‐like form. Three polymers with strict alternating purine‐pyrimidine sequences and GC content from 100—0% have been tested: poly(dG—dC)·poly(dG—dC), poly(dA—dC)·poly(dG—dT) and poly(dA—dT)·poly(dA—dT). The titrations by Nt and Dst‐3 were followed by circular dichroism. Although specific binding of Nt to the Z‐form of poly(dG—dC)·poly(dG—dC) does not occur, Nt reverses this Z structure to the B‐type conformation; Dst‐3 is, however, totally inefficient. The presumed non‐B or Z‐like structure of poly(dA—dC)·poly(dG—dT) is reversed to the B‐form upon interaction with Nt; Dst‐3 also induces this reversal but at higher ligand ratios. The modified B‐structure of poly(dA—dT)·poly(dA—dT) in low water activity is efficiently reversed to the B‐form by interaction with both Nt and Dst‐3.