Metabolism of phosphatidylglycerol in cell-free extracts of Escherichia coli.

Cell-free extracts from Escherichia coli strain number 9, lacking among other enzymes glycerol kinase, are able to incorporate [2-3H] glycerol into phospholipids. The characteristics of this incorporation indicate that it is not taking place through the regular glycerol phosphate pathway of phospholipid synthesis which occurs when this compound is used as a precursor or even when extracts of E. coli strain 7, having a functional glycerol kinase, are incubated with [2-3H] glycerol. In E. coli strain 9 extracts glycerol is exclusively incorporated into the distal position of phosphatidyl-glycerol while in the other strains the middle position glycerol is partially labelled.