RESUMEN

The isochorismate synthase DhbC from Bacillus anthracis is essential for the biosynthesis of the siderophore bacillibactin by this pathogenic bacterium. The structure of the selenomethionine-substituted protein was determined to 2.4 Šresolution using single-wavelength anomalous diffraction. B. anthracis DhbC bears the strongest resemblance to the Escherichia coli isochorismate synthase EntC, which is involved in the biosynthesis of another siderophore, namely enterobactin. Both proteins adopt the characteristic fold of other chorismate-utilizing enzymes, which are involved in the biosynthesis of various products, including siderophores, menaquinone and tryptophan. The conservation of the active-site residues, as well as their spatial arrangement, suggests that these enzymes share a common Mg(2+)-dependent catalytic mechanism.

Asunto(s)

Bacillus anthracis/química , Proteínas Bacterianas/química , Transferasas Intramoleculares/química , Magnesio/química , Oligopéptidos/química , Sideróforos/química , Secuencia de Aminoácidos , Bacillus anthracis/enzimología , Bacillus anthracis/genética , Proteínas Bacterianas/metabolismo , Dominio Catalítico , Cationes Bivalentes , Secuencia Conservada , Cristalografía por Rayos X , Enterobactina/biosíntesis , Enterobactina/química , Escherichia coli/química , Escherichia coli/enzimología , Escherichia coli/genética , Transferasas Intramoleculares/metabolismo , Magnesio/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Oligopéptidos/biosíntesis , Pliegue de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Selenometionina/química , Selenometionina/metabolismo , Sideróforos/biosíntesis , Homología Estructural de Proteína