IDENTIFICATION OF A PHOSPHOENOLPYRUVATE - FRUCTOSE PHOSPHOTRANSFERASESYSTEM (FRUCTOSE-1-PHOSPHATE FORMING) IN LISTERIA-MONOCYTOGENES

Listeria monocytogeneS is a gram-positive bacterium whose carbohydrate metabolic pathways are poorly understood. We provide evidence for an inducible phosphoenolpyruvate (PEP):fructose phosphotransferase system (PTS) in this pathogen. The system consists of enzyme I, HPr, and a f ructose-specific enzyme II complex which generates fructose-1-phosphat e as the cytoplasmic product of the PTS-catalyzed vectorial phosphoryl ation reaction. Fructose-1-phosphate kinase then converts the product of the PTS reaction to fructose-1,6-bisphosphate. HPr was shown to be phosphorylated by [P-32]PEP and enzyme I as well as by [P-32]ATP and a fructose-1,6-bisphosphate-activated HPr kinase like those found in ot her gram-positive bacteria. Enzyme I, HPr, and the enzyme II complex o f the Listeria PTS exhibit enzymatic cross-reactivity with PTS enzyme constituents from Bacillus subtilis and Staphylococcus aureus.