title: Recognition of triple-helical DNA structures by transposon Tn7.
abstract: We have found that the bacterial transposon Tn7 can recognize and preferentially insert adjacent to triple-helical nucleic acid structures. Both synthetic intermolecular triplexes, formed through the pairing of a short triplex-forming oligonucleotide on a plasmid DNA, and naturally occurring mirror repeat sequences known to form intramolecular triplexes or H-form DNA are preferential targets for Tn7 insertion in vitro. This target site selectivity depends upon the recognition of the triplex region by a Tn7-encoded ATP-using protein, TnsC, which controls Tn7 target site selection: the interaction of TnsC with the triplex region results in recruitment and activation of the Tn7 transposase. Recognition of a nucleic acid structural motif provides both new information into the factors that influence Tn7's target site selection and broadens its targeting capabilities.
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Rao
authors.forename: P S
authors.initials: PS
authors.lastname: Miller
authors.forename: N L
authors.initials: NL
authors.lastname: Craig
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D018983:DNA Footprinting; D004251:DNA Transposable Elements; D009690:Nucleic Acid Conformation; D010957:Plasmids
chemical_list: D004251:DNA Transposable Elements; C051802:triplex DNA; D004247:DNA