Abstract
The Tn7 transposon avoids inserting into a target DNA that contains a pre-existing copy of Tn7. This phenomenon, known as 'target immunity', is established when TnsB, a Tn7 transposase subunit, binds to Tn7 sequences in the target DNA and mediates displacement of TnsC, a critical transposase activator, from the DNA. Paradoxically, TnsB-TnsC interactions are also required to promote transposon insertion. We have probed Tn7 target immunity by isolating TnsB mutants that mediate more frequent insertions into a potentially immune target DNA because they fail to provoke dissociation of TnsC from the DNA. We show that a single region of TnsB mediates the TnsB-TnsC interaction that underlies both target immunity and transposition, but that TnsA, the other transposase subunit, channels the TnsB-TnsC interaction toward transposition.
Original language | English (US) |
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Pages (from-to) | 5904-5917 |
Number of pages | 14 |
Journal | EMBO Journal |
Volume | 22 |
Issue number | 21 |
DOIs | |
State | Published - Nov 3 2003 |
Externally published | Yes |
Keywords
- DNA transposition
- Enzyme activation
- Target immunity
- Tn7
- Transposase
ASJC Scopus subject areas
- General Neuroscience
- Molecular Biology
- General Biochemistry, Genetics and Molecular Biology
- General Immunology and Microbiology