Erwan Gueguen

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Type VI secretion systems (T6SS) are macromolecular, transenvelope machines encoded within the genomes of most Gram-negative bacteria, including plant, animal, and human pathogens, as well as soil and environmental isolates. T6SS are involved in a broad variety of functions: from pathogenesis to biofilm formation and stress sensing. This large array of(More)
The Yersinia enterocolitica phage-shock-protein (Psp) stress response system is activated by mislocalized outer-membrane secretin components of protein export systems and is essential for virulence. The cytoplasmic membrane proteins PspB and PspC were proposed to be dual function components of the system, acting both as positive regulators of psp gene(More)
Studies of several transposable genetic elements have pinpointed the importance of the transpososome, a nucleoprotein complex involving the transposon ends and a transposon-encoded enzyme--the transposase--as a key in regulating transposition. Transpososomes provide a precise architecture within which the chemical reactions involved in transposon(More)
The Type VI secretion system (T6SS) is a macromolecular complex widespread in Gram-negative bacteria. Although several T6SS are required for virulence towards host models, most are necessary to eliminate competitor bacteria. Other functions, such as resistance to amoeba predation, biofilm formation or adaptation to environmental conditions have also been(More)
Regulation of the bacterial phage-shock-protein (Psp) system involves communication between integral (PspBC) and peripheral (PspA) cytoplasmic membrane proteins and a soluble transcriptional activator (PspF). In this study protein subcellular localization studies were used to distinguish between spatial models for this putative signal transduction pathway(More)
The transposase of IS911, a member of the IS3 family of bacterial insertion sequences, is composed of a catalytic domain located at its C-terminal end and a DNA binding domain located at its N-terminal end. Analysis of the transposases of over 60 members of the IS3 family revealed the presence of a helix-turn-helix (HTH) motif within the N-terminal region.(More)
The type VI secretion system (T6SS) is a versatile secretion machine dedicated to various functions in Gram-negative bacteria, including virulence toward eukaryotic cells and antibacterial activity. Activity of T6SS might be followed in vitro by the release of two proteins, Hcp and VgrG, in the culture supernatant. Citrobacter rodentium, a rodent pathogen,(More)
The Yersinia enterocolitica phage shock protein (Psp) stress response is essential for virulence and for survival during the mislocalization of outer membrane secretin proteins. The cytoplasmic membrane proteins PspB and PspC are critical components involved in regulating psp gene expression and in facilitating tolerance to secretin-induced stress.(More)
The detection of nickel in water is of great importance due to its harmfulness for living organism. A way to detect Ni is the use of whole-cell biosensors. The aim of the present work was to build a light-emitting bacterial biosensor for the detection of Ni with high specificity and low detection limit properties. For that purpose, the regulatory circuit(More)
IS911 naturally produces transposase (OrfAB) derivatives truncated at the C-terminal end (OrfAB-CTF) and devoid of the catalytic domain. A majority species, OrfAB*, was produced at higher levels at 42 degrees C than at 30 degrees C suggesting that it is at least partly responsible for the innate reduction in IS911 transposition activity at higher(More)