The interaction of manganese ions with DNA.


We present the structure of the duplex formed by a fragment of auto-complementary DNA with the sequence d(CGTTAATTAACG). The structure was determined by X-ray crystallography. Up to date it is the first structure presenting the interaction between a DNA oligonucleotide and manganese ions. The presence of Mn2+ creates bonds among the N7 atom of guanines and phosphates. These bonds stabilize and determine the crystallographic network in a P3(2) space group, unusual in oligonucleotide crystals. The crystal structure observed is compared with those found in the presence of Mg2+, Ca2+ and Ni2+, which show different kinds of interactions. The double helices show end-to-end interactions, in a manner that the terminal guanines interact with the minor groove of the neighboring duplex, while the terminal cytosines are disordered. We have chosen this sequence since it contains a TTAA repeat. Such repeats are very rare in all genomes. We suggest that this sequence may be very susceptible to the formation of closely spaced thymine dimers.

DOI: 10.1016/j.jinorgbio.2009.03.004

Cite this paper

@article{Millonig2009TheIO, title={The interaction of manganese ions with DNA.}, author={Hans Millonig and Joan Pous and Catherine Gouyette and Juan A. Subirana and Jennifer L. Campos}, journal={Journal of inorganic biochemistry}, year={2009}, volume={103 6}, pages={876-80} }