%0 Journal Article
%T A model for the molecular organisation of the IS911 transpososome
%A Philippe Rousseau
%A Catherine Tardin
%A Nathalie Tolou
%A Laurence Salom¨¦
%A Mick Chandler
%J Mobile DNA
%D 2010
%I BioMed Central
%R 10.1186/1759-8753-1-16
%X Transposons are ubiquitous. They have had and continue to exert a major effect on genome architecture, gene expression and organisation. Tight regulation of their activity is essential to limit damage they may cause by generating potentially lethal DNA rearrangements. Indeed, their study has provided many examples of judicious regulatory mechanisms that are used to achieve this [1].A crucial checkpoint in transposition is the assembly of the 'transpososome'. This step is a general prerequisite for initiating DNA cleavage and the subsequent chemical steps in transposition, for most elements that use a DNA transposition intermediate. In this protein-DNA complex, both ends of the transposon are bridged by an element-specific enzyme, the transposase, which catalyses the DNA strand cleavages and strand transfers necessary for transposon mobility [2]. The transpososome adopts very precise architectures to accomplish these steps, and undergoes defined changes throughout the transposition process. Such conformational changes have been observed within the transpososome of IS50 [3-5], the bacteriophage Mu (which requires three of four specific transposase binding sites) [6] and Tn10 (whose transpososome shows an increase in stability as it assembles) [7,8]. Moreover, for both IS50 and Mu, a transposase molecule binds to one end but is catalytically active only on the other transposon end. This arrangement ensures that cleavage does not occur [6] before the correct complex has been assembled [9,10]. In spite of its key importance, the composition and organisation of such assemblies have been examined for only a handful of transposable elements [2,11] and with varying degrees of detail.In this study, we examined the transposition properties of the bacterial insertion sequence, IS911 [12]. Bacterial insertion sequences (IS) are among the smallest autonomous transposable elements. IS911 belongs to the largest known family of ISs, the IS3 family (ISfinder: http://www-is.biotoul.fr
%U http://www.mobilednajournal.com/content/1/1/16