Parallel-stranded duplex DNA containing dA · dU base pairs

✍ Scribed by Ingo Förtsch; Hartmut Fritzsche; Eckhard Birch-Hirschfeld; Elisabeth Evertsz; Reinhard Klement; Thomas M. Jovin; Christoph Zimmer

• Book ID: 102650635
• Publisher: Wiley (John Wiley & Sons)
• Year: 1998
• Tongue: English
• Weight: 1017 KB
• Volume: 38
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/(sici)1097-0282(199602)38:2<209::aid-bip7>3.0.co;2-z

✦ Synopsis

DNA o1igoniiclc.otide.s with dA and dU residues can jbrm diiplexes with trans d ( A . U ) base pairing and the siigur-phosphufe backbone in a parallel-srranded orimtation, as previously established ,f& oiigoniiclcotidcs with d(A . T ) base pairs. The propertie.s cf such parallelstranded DNA (ps-DNA) 25-mer duplaes have been characterized by absorption (uv) , CD, ir, andfliiort~scence spectroscopy, as well as by nucleuse sensitivity Comparisons were made with duplex moleailt~s conraining (a) d T in both strands, ( b ) dU in one strand and d T in the second, and (c) the same base combinations in reference antiparallel-.~tranded (ups) .structures. Thermodvnumic ana1y.si.s revealed that total replacement of deoxythymine by deoxyuridine was accompanied by dt>.stahilization ofthe ps-helix (reduction in T, by -13°C in 2 mM MgCI,, 10 mM Nu-cacodylate). The U-containing ps-helix (U1 . U2) also melted 14°C lower than the corresponding ups-helix under the same ionic conditions; this dlference was very close to that