Abstract
Tn7 insertion into its specific target site, attTn7, is mediated by the proteins TnsA, TnsB, TnsC and TnsD. The double-strand breaks that separate Tn7 from the donor DNA require the Tns proteins, the transposon and an attTn7 target DNA, suggesting that a prerequisite for transposition is the formation of a nucleoprotein complex containing TnsABC+D, and these DNAs. Here, we identify a TnsABC+D transposon-attTn7 complex, and demonstrate that it is a transposition intermediate. We demonstrate that an interaction between TnsB, the transposase subunit that binds to the transposon ends, and TnsC, the target DNA-binding protein that controls the activity of the transposase, is essential for assembly of the TnsABC+D transposon-attTn7 complex. We also show that certain TnsB residues are required for recombination because they mediate a TnsB-TnsC interaction critical to formation of the TnsABC+D transposon-attTn7 complex. We demonstrate that TnsA, the other transposase subunit, which also interacts with TnsC, greatly stabilizes the TnsABC+D transposon-attTn7 complex. Thus multiple interactions between the transposase subunits, TnsA and TnsB, and the target-binding transposase activator, TnsC, control Tn7 transposition.
Original language | English (US) |
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Pages (from-to) | 3494-3504 |
Number of pages | 11 |
Journal | EMBO Journal |
Volume | 21 |
Issue number | 13 |
DOIs | |
State | Published - Jul 1 2002 |
Keywords
- DNA transposition
- DNA-protein complex
- Enzyme activation
- Tn7
- Transposase
ASJC Scopus subject areas
- General Neuroscience
- Molecular Biology
- General Biochemistry, Genetics and Molecular Biology
- General Immunology and Microbiology