Tertiary structure motif of Oxytricha telomere DNA.
The tertiary structure of a single-stranded DNA containing the sequence of Oxytricha telomere DNA has been determined. This DNA adopts a compact tertiary structure that consists of four base-paired tetrads of guanine residues which are connected by three loops. The tetrads show significant deviations from planarity, and two of the loops exhibit significant loop-loop interactions. The structure of this telomere contains syn-thymine residues, which are in the loops, as well as an intraloop pyrimidine-pyrimidine base pair between residues that are separated by a single residue. The tertiary structure of the telomere DNA is consistent with prior results that showed that two thymines distant in sequence could be photo-cross-linked. The overall folding pattern of this telomere DNA is similar to that previously determined for a DNA aptamer, which binds to and inhibits thrombin, though the details of the two structures are quite distinct.
Wang
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Chemistry Department, Wesleyan University, Middletown, Connecticut 06459.
Swaminathan
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Bolton
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D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D003432:Cross-Linking Reagents; D016054:DNA, Protozoan / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry; D004355:Drug Stability; D006358:Hot Temperature; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D016813:Oxytricha / Q000235:genetics*; D016615:Telomere / Q000737:chemistry*
D003432:Cross-Linking Reagents; D016054:DNA, Protozoan; D004277:DNA, Single-Stranded