Structure of Z-DNA in solution. A flow linear dichroism study

Abstract

U.v. flow linear dichroism (L.D.) of the high-salt form of duplex poly(dG-dC)(‘Z-DNA’) shows that the reduced dichroism of Z-DNA is about twice as large as for B-DNA and the spectrum has the shape expected for Watson–Crick base-pairs oriented perpendicular to the helix; axis spectral features observed during the B→Z conversion are in qualitative agreement with a mechanism in which the base-pairs flip 180° around the glycosyl bonds.