- Wang AJ, Quigley GJ, Kolpak FJ, van der Marel G, van Boom JH, Rich A
- Left-handed double helical DNA: variations in the backbone conformation.
- Science. 1981 Jan 9;211(4478):171-6.
- Four different crystals of d(CpGpCpGpCpG) have been solved by x-ray diffraction analysis and all form similar left-handed double helical Z-DNA molecules in the crystal lattice. Two different conformations are observed for the phosphates in the GpC sequences, as the phosphates are found either facing the helical groove or rotated away from it. The latter conformation is often found when hydrated magnesium ions are complexed to a phosphate oxygen atom. These different conformations may be used when right-handed B-DNA joins left-handed Z-DNA. Atomic coordinates and torsion angles are presented for both types of Z-DNA.