Evidence for the allosteric regulation of bacterial glycogen synthesis in vivo

Abstract

In stationary-phase cultures of either Escherichia coli W4597(K) or G34 in various nutrient conditions there is a 10-fold range of steady-state rates of glycogen synthesis with an essentially constant steady-state level of ATP, presumably reflecting an essentially constant energy charge. The steady-state level of fructose-1,6-diphosphate in these cultures varies from experiment to experiment as a function of the observed rate of glycogen synthesis. These data were fitted to the Hill equation using an assumed Hill coefficient of 2: a plot of [Fru- P 2] 2/ rate of glycogen synthesis versus [Fru- P 2] 2 is linear with a correlation coefficient greater than 0.999, indicating a causal relationship between the concentration of Fru- P 2 and the rate of glycogen synthesis. These data provide further evidence that allosteric effects observed in vitro function in vivo.