The Role of Phosphatidylglycerol in the Vectorial Phosphorylation of Sugar by Isolated Bacterial Membrane Preparations

Abstract

Phospholipase D (cabbage) inhibits the vectorial phosphorylation of alpha-methylglucoside by isolated membrane preparations from Escherichia coli ML 308-225 without increasing the efflux of intramembranal alpha-methylglucoside-P. This effect is shown to be related to the ability of phospholipase D to hydrolyze membrane phosphatidylglycerol specifically. After treatment with phospholipase D, the membranes resynthesize phosphatidylglycerol with a return in their ability to take up alpha-methylglucoside. Since proline uptake by the same preparations is only slightly inhibited by phospholipase D, the data indicate that phosphatidylglycerol is required specifically for transport processes which are mediated by the P-enolpyruvate-P-transferase system.