title: Synthesis and characterization of topologically linked single-stranded DNA rings.
abstract: We investigated the synthesis of linked-ring DNAs by two DNA-ligation-based methods. In the first method, two DNA oligonucleotides were associated through a duplex segment of more than a full helical turn. Circularization of the entwined oligonucleotides by T4 DNA ligase resulted in two linked-ring DNAs with a total yield of approximately 40%. In the second method, a DNA oligonucleotide was circularized over a circular DNA template, resulting in the formation of approximately 10% linked-ring product. The circular nature of linked-ring DNAs was verified with exonuclease digestion and the existence of topological linkages was demonstrated by analyzing the electrophoretic mobility pattern of DNA products obtained from the digestion of each linked-ring DNA using specific restriction endonucleases. A linked-ring DNA library in which one of the two rings contained random-sequence nucleotides was also constructed and tested for compatibility with in vitro selection.
authors.affiliation: Department of Biochemistry, McMaster University, Health Sciences Center, 1200 Main Street West, Hamilton, Ont, Canada L8N 3Z5.
authors.forename: Lieven P
authors.initials: LP
authors.lastname: Billen
authors.forename: Yingfu
authors.initials: Y
authors.lastname: Li
mesh_terms: D020029:Base Pairing; D001483:Base Sequence; D011088:DNA Ligases / Q000737:chemistry*; D043864:DNA, Catenated / Q000138:chemical synthesis* / Q000737:chemistry; D004270:DNA, Circular / Q000138:chemical synthesis* / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000138:chemical synthesis* / Q000737:chemistry; D015723:Gene Library; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry
chemical_list: D043864:DNA, Catenated; D004270:DNA, Circular; D004277:DNA, Single-Stranded; D009841:Oligonucleotides; D011088:DNA Ligases