Transposase-transposase interactions in MOS1 complexes: a biochemical approach.
Transposases are proteins that have assumed the mobility of class II transposable elements. In order to map the interfaces involved in transposase-transposase interactions, we have taken advantage of 12 transposase mutants that impair mariner transposase-transposase interactions taking place during transposition. Our data indicate that transposase-transposase interactions regulating Mos1 transposition are sophisticated and result from (i) active MOS1 dimerization through the first HTH of the N-terminal domain, which leads to inverted terminal repeat (ITR) binding; (ii) inactive dimerization carried by part of the C-terminal domain, which prevents ITR binding; and (iii) oligomerization. Inactive dimers are nonpermissive in organizing complexes that produce ITR binding, but the interfaces (or interactions) supplied in this state could play a role in the various rearrangements needed during transposition. Oligomerization is probably not due to a specific MOS1 domain, but rather the result of nonspecific interactions resulting from incorrect folding of the protein. Our data also suggest that the MOS1 catalytic domain is a main actor in the overall organization of MOS1, thus playing a role in MOS1 oligomerization. Finally, we propose that MOS1 behaves as predicted by the pre-equilibrium existing model, whereby proteins are found to exist simultaneously in populations with diverse conformations, monomers and active and inactive dimers for MOS1. We were able to identify several MOS1 mutants that modify this pre-existing equilibrium. According to their properties, some of these mutants will be useful tools to break down the remaining gaps in our understanding of mariner transposition.
Université François Rabelais de Tours, GICC, CNRS, UMR 6239, UFR Sciences & Techniques, Parc Grandmont, 37200 Tours, France.
Guillaume
G
Carpentier
Jérome
J
Jaillet
Aude
A
Pflieger
Jérémy
J
Adet
Sylvaine
S
Renault
Corinne
C
Augé-Gouillou
D000595:Amino Acid Sequence; D020134:Catalytic Domain; D004251:DNA Transposable Elements / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D019281:Dimerization; D008954:Models, Biological; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017510:Protein Folding; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D020836:Protein Structure, Quaternary; D020079:Terminal Repeat Sequences; D019895:Transposases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins; D050505:Mutant Proteins; C111652:mariner transposases; D019895:Transposases