Evelyne Couture-Tosi

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Endosporulation is an ancient bacterial developmental program that culminates with the differentiation of a highly resistant endospore. In the model organism Bacillus subtilis, gene expression in the forespore and in the mother cell, the two cells that participate in endospore development, is governed by cell type-specific RNA polymerase sigma subunits.(More)
Bacillus anthracis, the aetiological agent of anthrax, is a Gram-positive spore-forming bacterium. The exosporium is the outermost integument surrounding the mature spore. Here, we describe the purification and the characterization of an immunodominant protein of the spore surface. This protein was abundant, glycosylated and part of the exosporium. The(More)
We recently identified a Bacillus anthracis glycoprotein which is a structural constituent of the exosporium filaments (P. Sylvestre, E. Couture-Tosi, and M. Mock, Mol. Microbiol. 45:169-178, 2002). This Bacillus collagen-like protein (BclA) contains an internal collagen-like region (CLR) of GXX repeats which includes a large proportion of GPT triplets.(More)
Spores of Bacillus anthracis, the etiological agent of anthrax, and the closely related species Bacillus cereus and Bacillus thuringiensis, possess an exosporium, which is the outermost structure surrounding the mature spore. It consists of a paracrystalline basal layer and a hair-like outer layer. To date, the structural contribution of only one exosporium(More)
The exon-intron structure of the human complement C1s gene displays a striking similarity with that of the gene encoding haptoglobin, a peculiar transport protein distantly related to the serine proteases. While the protease regions of the serine zymogens are typically encoded by multiple exons, the protease domains of C1s and of its genetically linked and(More)
We report on the first step in mapping out the spatial location of structural proteins within the exosporium, namely a description of its three-dimensional architecture. Using electron microscopy and image analysis, we have characterized crystalline fragments from the exosporium of Bacillus cereus, B. thuringiensis and B. anthracis strains and identified up(More)
Adjustment of the synthesis of abundant protein to the requirements of the cell involves processes critical to the minimization of energy expenditure. The regulation of S-layer genes might be a good model for such processes because expression must be controlled, such that the encoded proteins exactly cover the surface of the bacterium. Bacillus anthracis(More)
Bacillus anthracis, a gram-positive, spore-forming bacterium, is the etiological agent of anthrax. It belongs to the Bacillus cereus group, which also contains Bacillus cereus and Bacillus thuringiensis. Most B. anthracis strains are sensitive to phage gamma, but most B. cereus and B. thuringiensis strains are resistant to the lytic action of phage gamma.(More)
Surface layers (S-layers), which form the outermost layers of many Bacteria and Archaea, consist of protein molecules arranged in two-dimensional crystalline arrays. Bacillus anthracis, a gram-positive, spore-forming bacterium, responsible for anthrax, synthesizes two abundant surface proteins: Sap and EA1. Regulatory studies showed that EA1 and Sap appear(More)
LamB is one of the major cellular proteins when E. coli is grown in the presence of maltose and is localized in the outer membrane. Previous immunolabellings obtained with monoclonal antibodies showed that this protein is a transmembrane protein and led to the detection of 4 epitopes exposed on the cell surface and 2 located on the inner surface of the(More)