Salt-induced isomerization of a synthetic RNA poly[r(A-U)]

✍ Scribed by Michaela Vorlíčková; Jaroslav Kypr; Thomas M. Jovin

• Book ID: 101718927
• Publisher: Wiley (John Wiley & Sons)
• Year: 1988
• Tongue: English
• Weight: 229 KB
• Volume: 27
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360270214

✦ Synopsis

Since the beginning of the 1970s several laboratories have demonstrated that high concentrations of monovalent salts induce isomerizations involving different types of double helices in synthetic DNA molecules with alternating purine-pyrimidine sequences.'-8 A notable example is the transition between the right-handed Band left-handed Z-helical conformations (reviewed in Refs. 9 and 10). Such a process also occurs with RNA, as shown recently in the reported A to Z isomerization of poly[r(G-C)]>'-13 The left-handed form of poly[r(G-C)] was called Z-RNA to indicate that its structural properties (reviewed in Ref. 14) are similar to those of Z-DNA. Poly[d(A-T)]'-, and p~ly[d(A-U)]'~ do not assume the Z-conformation in aqueous solution under conditions reported to date. Thus, one would infer that poly[r(A-U)] is also not likely to isomerize to Z-RNA. In this communication we report CD observations that may not support this expectation.