Unexpected A-form formation of 4'-thioDNA in solution, revealed by NMR, and the implications as to the mechanism of nuclease resistance.

ABSTRACT: Fully modified 4'-thioDNA, an oligonucleotide only comprising 2'-deoxy-4'-thionucleosides, exhibited resistance to an endonuclease, in addition to preferable hybridization with RNA. Therefore, 4'-thioDNA is promising for application as a functional oligonucleotide. Fully modified 4'-thioDNA was found to behave like an RNA molecule, but no details of its structure beyond the results of circular dichroism analysis are available. Here, we have determined the structure of fully modified 4'-thioDNA with the sequence of d(CGCGAATTCGCG) by NMR. Most sugars take on the C3'-endo conformation. The major groove is narrow and deep, while the minor groove is wide and shallow. Thus, fully modified 4'-thioDNA takes on the A-form characteristic of RNA, both locally and globally. The only structure reporte

SUBMITTER: Matsugami A 

PROVIDER: S-EPMC2330235 | biostudies-literature | 2008 Apr

REPOSITORIES: biostudies-literature