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

Genes Dev. 2001 Mar 15;15(6):737-47. doi: 10.1101/gad.870201.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Blotting, Western
  • DNA / metabolism*
  • DNA Replication
  • DNA Transposable Elements / genetics*
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins*
  • Models, Genetic
  • Molecular Sequence Data
  • Mutation*
  • Plasmids / metabolism
  • Polymerase Chain Reaction
  • Protein Binding
  • Sequence Homology, Amino Acid

Substances

  • DNA Transposable Elements
  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • TnsE protein, E coli
  • DNA