Systematic Investigation of the Escherichia coli Metabolome for the Biosynthetic Origin of an Isocyanide Carbon Atom

Feeding studies were conducted in which E. coli metabolism was controlled through the systematic use of strains that carry mutations in primary metabolic pathways, thus allowing the origin of the isocyanide carbon atom in antibiotic 1 to be determined. This carbon atom was shown to be derived from the C2 atom of ribulose-5P, or a tautomerically equivalent sugar (see scheme; isnA and isnB are the genes responsible for the biosynthetic pathway of 1).