Tn7 recognizes transposition target structures associated with DNA replication using the DNA-binding protein TnsE

• Published in: Genes & development Vol. 15; no. 6; pp. 737 - 747
• Main Authors: Peters, J E, Craig, N L
• Format: Journal Article
• Language: English
• Published: United States Cold Spring Harbor Laboratory Press 15.03.2001
• Subjects: Alleles; Amino Acid Sequence; Blotting, Western; DNA - metabolism; DNA Replication; DNA Transposable Elements - genetics; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Escherichia coli; Escherichia coli - metabolism; Escherichia coli Proteins; Models, Genetic; Molecular Sequence Data; Mutation; Plasmids - metabolism; Polymerase Chain Reaction; Protein Binding; Research Paper; Sequence Homology, Amino Acid; TnsE protein; transposon Tn7
• ISSN: 0890-9369; 1549-5477
• DOI: 10.1101/gad.870201

We report that the bacterial transposon Tn7 selects targets by recognizing features associated with DNA replication using the transposon-encoded DNA-binding protein TnsE. We show that Tn7 transposition directed by TnsE occurs in one orientation with respect to chromosomal DNA replication, indicating that a structure or complex involved in DNA replication is likely to be a critical determinant of TnsE insertion. We find that mutant TnsE proteins that allow higher levels of transposition also bind DNA better than the wild-type protein. The increased binding affinity displayed by the TnsE high-activity mutants indicates that DNA binding is relevant to transposition activity and suggests that TnsE interacts directly with target DNAs. In vitro, TnsE interacts preferentially with certain DNA structures, indicating a mechanism for the TnsE-mediated orientation and insertion preference. The pattern of TnsE-mediated insertion events around the Escherichia coli chromosome provides insight into how DNA replication forks proceed in vivo.