Biophysical Journal 71: 1530-1538 (1996)
© 1996 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Vorlícková, M Articles by Kypr, J Search for Related Content PubMed PubMed Citation Articles by Vorlícková, M Articles by Kypr, J

Comparison of the solution and crystal conformations of (G + C)-rich fragments of DNA.

Institute of Biophysics, Czech Academy of Sciences, Brno, Czech Republic.

ABSTRACT

DNA fragments crystallize in an unpredictable manner, and relationships between their crystal and solution conformations still are not known. We have studied, using circular dichroism spectroscopy, solution conformations of (G + C)-rich DNA fragments, the crystal structures of which were solved in the laboratory of one of the present authors. In aqueous trifluorethanol (TFE) solutions, all of the examined oligonucleotides adopted the same type of double helix as in the crystal. Specifically, the dodecamer d(CCCCCGCGGGGG) crystalized as A-DNA and isomerized into A-DNA at high TFE concentrations. On the other hand, the hexamer d(CCGCGG) crystallized in Z-form containing tilted base pairs, and high TFE concentrations cooperatively transformed it into the same Z-form as adopted by the RNA hexamer r(CGCGCG), although d(CCGCGG) could isomerize into Z-DNA in the NaCl + NiCl2) aqueous solution. The fragments crystallizing as B-DNA remained B-DNA, regardless of the solution conditions, unless they denatured or aggregated. Effects on the oligonucleotide conformation of 2-methyl-2,4-pentanediol and other crystallization agents were also studied. 2-Methyl-2,4-pentanediol induced the same conformational transitions as TFE but, in addition, caused an oligonucleotide condensation that was also promoted by the other crystallization agents. The present results indicate that the crystal double helices of DNA are stable in aqueous TFE rather than aqueous solution.

This article has been cited by other articles:

				D. A. Adamiak, W. R. Rypniewski, J. Milecki, and R. W. Adamiak The 1.19 A X-ray structure of 2'-O-Me(CGCGCG)2 duplex shows dehydrated RNA with 2-methyl-2,4-pentanediol in the minor groove Nucleic Acids Res., October 15, 2001; 29(20): 4144 - 4153. [Abstract] [Full Text] [PDF]