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The kinetic and molecular properties of cyanobacterial glucose-6-phosphate dehydrogenase, partly purified from Anabaena sp. ATCC 27893, show that it undergoes relatively slow, reversible transitions between different aggregation states which differ in catalytic activity. Sucrose gradient centrifugation and polyacrylamide gel electrophoresis reveal three(More)
Malonyl-CoA is an essential intermediate in fatty acid synthesis in all living cells. Here we demonstrate a new role for this molecule as a global regulator of lipid homeostasis in Gram-positive bacteria. Using in vitro transcription and binding studies, we demonstrate that malonyl-CoA is a direct and specific inducer of Bacillus subtilis FapR, a conserved(More)
Structural genomics is a new approach in functional assignment of proteins identified via whole-genome sequencing programs. Its rationale is that nonhomologous proteins performing similar or related biological functions might have similar tertiary structure. We used dye pseudoaffinity chromatography, two-dimensional gel electrophoresis, and mass(More)
Mycobacterial phosphatidylinositol mannosides (PIMs) and metabolically derived cell wall lipoglycans play important roles in host-pathogen interactions, but their biosynthetic pathways are poorly understood. Here we focus on Mycobacterium smegmatis PimA, an essential enzyme responsible for the initial mannosylation of phosphatidylinositol. The structure of(More)
Mutagenized dockerin domains of endoglucanase CelD (type I) and of the cellulosome-integrating protein CipA (type II) were constructed by swapping residues 10 and 11 of the first or the second duplicated segment between the two polypeptides. These residues have been proposed to determine the specificity of cohesin-dockerin interactions. The dockerin domain(More)
Protein phosphorylation transduces a large set of intracellular signals. One mechanism by which phosphorylation mediates signal transduction is by prompting conformational changes in the target protein or interacting proteins. Previous work described an allosteric site mediating phosphorylation-dependent activation of AGC kinases. The AGC kinase PDK1 is(More)
Phosphatidyl-myo-inositol mannosyltransferase A (PimA) is an essential glycosyltransferase (GT) involved in the biosynthesis of phosphatidyl-myo-inositol mannosides (PIMs), which are key components of the mycobacterial cell envelope. PimA is the paradigm of a large family of peripheral membrane-binding GTs for which the molecular mechanism of(More)
Phospho-Ser/Thr protein phosphatases (PPs) are dinuclear metalloenzymes classed into two large families, PPP and PPM, on the basis of sequence similarity and metal ion dependence. The archetype of the PPM family is the alpha isoform of human PP2C (PP2Calpha), which folds into an alpha/beta domain similar to those of PPP enzymes. The recent structural(More)
To locate the region involved in binding dockerin domains, 15 mutations were introduced across the surface of the seventh cohesin domain of the scaffolding protein CipA, which holds together the cellulosome of Clostridium thermocellum. Mutated residues were located on both faces of the nine-stranded beta-sandwich forming the cohesin domain and on the loops(More)
We engineered a class of proteins that binds selected polypeptides with high specificity and affinity. Use of the protein scaffold of Sac7d, belonging to a protein family that binds various ligands, overcomes limitations inherent in the use of antibodies as intracellular inhibitors: it lacks disulfide bridges, is small and stable, and can be produced in(More)