As far as I understand Tn3 transposons jump around via replicative transposition. This involves a transposase encoded by Tn3 elements binding inverted repeats either side of the transposon and then mediating the replication of the sequence between these sites into a donor genome-site. This however, forms an intermediate fusion molecule between the donor and recipient. In the next step resolution happens releasing the original donor and the recipient now containing a copy of the transposon. This is mediated by a resolvase protein also encoded by the transposon, and this recognises the 'res' sequence in the transposon DNA. Thats if I haven't totally misunderstood.
If you have a gene flanked by the appropriate Inverted repeats but lacking the res sequence, could it still be transposed by tranpsposase/resolvase proteins expressed from another transposon somewhere else on the genome/plasmid?
Thanks!
I am not familiar with that exact transposon, but typically transposases work in cis and trans because once the transposes protein is produced it is agnostic about source or location of the inverted repeats it recognizes within the cell.
There is plenty of literature using such "uncoupled" transposon systems for gene integration/removal.
I do not know the answer to your question, but we have found some weird results in mycobacteria when cloning marker genes with inverted or direct repeats:
PLoS One. 2012;7(12):e51064. doi: 10.1371/journal.pone.0051064. Epub 2012 Dec 10. Direct and inverted repeats elicit genetic instability by both exploiting and eluding DNA double-strand break repair systems in mycobacteria. Wojcik EA1, Brzostek A, Bacolla A, Mackiewicz P, Vasquez KM, Korycka-Machala M, Jaworski A, Dziadek J.
The answer is YES. Donor and target replicons form a stable cointegrate if res is absent within the Tn region. I created mini transposons with IRs alone and provided TnpA in trans, and then measured transposition frequencies.
Article Complete Sequence Determination Combined with Analysis of Tr...
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