Mariner Mos1 transposase dimerizes prior to ITR binding.
The mariner Mos1 synaptic complex consists of a tetramer of transposase molecules that bring together the two ends of the element. Such an assembly requires at least two kinds of protein-protein interfaces. The first is involved in "cis" dimerization, and consists of transposase molecules bound side-by-side on a single DNA molecule. The second, which is involved in "trans" dimerization, consists of transposase molecules bound to two different DNA molecules. Here, we used biochemical and genetic methods to enhance the definition of the regions involved in cis and trans-dimerization in the mariner Mos1 transposase. The cis and trans-dimerization interfaces were both found within the first 143 amino acid residues of the protein. The cis-dimerization activity was mainly contained in amino acids 1-20. The region spanning from amino acid residues 116-143, and containing the WVPHEL motif, was involved in the cis- to trans-shift as well as in trans-dimerization stabilization. Although the transposase exists mainly as a monomer in solution, we provide evidence that the transposase cis-dimer is the active species in inverted terminal repeat (ITR) binding. We also observed that the catalytic domain of the mariner Mos1 transposase modulates efficient transposase-transposase interactions in the absence of the transposon ends.
Augé-Gouillou
Corinne
C
Laboratoire d'Etude des Parasites Génétiques, Université François Rabelais de Tours, EA 3868, UFR Sciences & Techniques, Parc Grandmont, 37200 Tours, France. auge@univ-tours.fr
Brillet
Benjamin
B
Germon
Stéphanie
S
Hamelin
Marie-Hélène
MH
Bigot
Yves
Y
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D020134:Catalytic Domain; D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins / Q000378:metabolism*; D019281:Dimerization; D046911:Macromolecular Substances; D011485:Protein Binding; D020079:Terminal Repeat Sequences; D019895:Transposases / Q000378:metabolism
D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; C111652:mariner transposases; D019895:Transposases