Abstract
The structures of single-stranded (ss) oligonucleotides containing (CAG)15 [ss(CAG)15] or (GAC)15 [ss(GAC)15] were examined. At 10 degrees C, the electrophoretic mobilites of the two DNAs were similar to ss(CTG)15, a DNA that forms a hairpin containing base paired and/or stacked thymines. At 37 degrees C in 50 mM NaCl, single-strand-specific P1 nuclease cleaved the G33-G36 phosphodiesters of ss(GAC)15, and the G32-A34, G35-C36 phosphodiesters of ss(CAG)15 (where the loop apex of both DNAs = A34). Electrophoretic mobility melting profiles indicated that the melting temperature (Tm) of ss(CAG)15 in low (approximately 1 mM Na+) ionic strength was 38 degrees C. In contrast, the Tm of ss(GAC)15 was 49 degrees C, a value similar to the Tm of ss(CTG)15. These results provide evidence that ss(GAC)15 and ss(CAG)15 form similar, but distinguishable hairpin structures.
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- Chen X., Mariappan S. V., Catasti P., Ratliff R., Moyzis R. K., Laayoun A., Smith S. S., Bradbury E. M., Gupta G. Hairpins are formed by the single DNA strands of the fragile X triplet repeats: structure and biological implications. Proc Natl Acad Sci U S A. 1995 May 23;92(11):5199–5203. doi: 10.1073/pnas.92.11.5199. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gacy A. M., Goellner G., Juranić N., Macura S., McMurray C. T. Trinucleotide repeats that expand in human disease form hairpin structures in vitro. Cell. 1995 May 19;81(4):533–540. doi: 10.1016/0092-8674(95)90074-8. [DOI] [PubMed] [Google Scholar]
- Maxam A. M., Gilbert W. Sequencing end-labeled DNA with base-specific chemical cleavages. Methods Enzymol. 1980;65(1):499–560. doi: 10.1016/s0076-6879(80)65059-9. [DOI] [PubMed] [Google Scholar]
- Mitas M., Yu A., Dill J., Kamp T. J., Chambers E. J., Haworth I. S. Hairpin properties of single-stranded DNA containing a GC-rich triplet repeat: (CTG)15. Nucleic Acids Res. 1995 Mar 25;23(6):1050–1059. doi: 10.1093/nar/23.6.1050. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robinson H., Wang A. H. 5'-CGA sequence is a strong motif for homo base-paired parallel-stranded DNA duplex as revealed by NMR analysis. Proc Natl Acad Sci U S A. 1993 Jun 1;90(11):5224–5228. doi: 10.1073/pnas.90.11.5224. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schlötterer C., Tautz D. Slippage synthesis of simple sequence DNA. Nucleic Acids Res. 1992 Jan 25;20(2):211–215. doi: 10.1093/nar/20.2.211. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wohlrab F. Enzyme probes in vitro. Methods Enzymol. 1992;212:294–301. doi: 10.1016/0076-6879(92)12018-l. [DOI] [PubMed] [Google Scholar]
- Yu A., Dill J., Wirth S. S., Huang G., Lee V. H., Haworth I. S., Mitas M. The trinucleotide repeat sequence d(GTC)15 adopts a hairpin conformation. Nucleic Acids Res. 1995 Jul 25;23(14):2706–2714. doi: 10.1093/nar/23.14.2706. [DOI] [PMC free article] [PubMed] [Google Scholar]