Unusual pattern of nucleoside polyphosphate hydrolysis by the acid phosphatase (optimum pH = 2.5) of Escherichia coli.

An acid phosphatase with an optimum pH of 2.5, was partially extracted by a single wash of whole cells of E. coli by 1 mM EDTA 50 mM Tris buffer pH 7.8. Its enrichment coefficient in this extract was about 100. Ribonucleoside polyphosphates were hydrolyzed by the enzyme at very different rates according both to the nature of the base and the position of the phosphate group. UTP and ppGpp were the most sensitive. The significance of these differences are briefly discussed.