Bending of oligonucleotides containing an isosteric nucleobase: 7-deaza-2'-deoxyadenosine replacing dA within d(A)6 tracts.
Decanucleotide duplexes of the parent sequence d(GGCA6C).d(CCGT6G) containing various numbers of 2'-deoxytubercidin (c7Ad) in place of 2'-deoxyadenosine have been synthesized. Phosphoramidites of protected c7Ad (3a,b) were used in automated solid-phase synthesis together with those of regular nucleosides. Upon enzymic 5'-phosphorylation and ligation, multimers of 5 and 7-11 were analyzed by polyacrylamide gel electrophoresis and compared with regard to intrinsic, sequence-directed bending. Replacement of dA by c7Ad within the oligomers decreased bending, but the extent depends strongly on the position of incorporation: strong bending was still observed if the 3'- and 5'-terminal dA residues of the dA tract were replaced while the interruption of the d(A)6 tract by c7Ad reduced bending strongly.
Seela
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Laboratorium für Organische und Bioorganische Chemie, Fachbereich Biologie/Chemie, Universität Osnabrück, Federal Republic of Germany.
Berg
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Rosemeyer
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D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000031:analogs & derivatives; D001483:Base Sequence; D003839:Deoxyadenosines; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis; D013056:Spectrophotometry, Ultraviolet; D014372:Tubercidin / Q000031:analogs & derivatives
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D003839:Deoxyadenosines; D007202:Indicators and Reagents; D009838:Oligodeoxyribonucleotides; C053222:2'-deoxytubercidin; D014372:Tubercidin