Abstract
The bacterial transposon Tn7 utilizes four Tn7-encoded proteins, TnsA, TnsB, TnsC and TnsD, to make insertions at a specific site termed attTn7. This target is selected by the binding of TnsD to attTn7 in a sequence-specific manner, followed by the binding of TnsC and activation of the transposase. We show that TnsD binding to attTn7 induces a distortion at the 5′ end of the binding site and TnsC contacts the region of attTn7 distorted by TnsD. Previous work has shown that a target site containing triplex DNA, instead of TnsD-attTn7, can recruit TnsABC and effect site-specific insertion of Tn7. We propose that the DNA distortion imposed by TnsD on attTn7, like the altered DNA structure via triplex formation, serves as a signal to recruit TnsC. We also show that TnsD primarily contacts the major groove of DNA, whereas TnsC is a minor groove binding protein. The footprint of the TnsC-TnsD-attTn7 nucleoprotein complex includes and extends beyond the Tn7 insertion site, where TnsC forms a platform to receive and activate the transposase to carry out recombination.
Original language | English (US) |
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Pages (from-to) | 924-932 |
Number of pages | 9 |
Journal | EMBO Journal |
Volume | 20 |
Issue number | 4 |
DOIs | |
State | Published - Feb 15 2001 |
Keywords
- DNA distortion
- Footprinting
- Protein-DNA
- Recombination
- Triplex
ASJC Scopus subject areas
- General Neuroscience
- Molecular Biology
- General Biochemistry, Genetics and Molecular Biology
- General Immunology and Microbiology