Fig. 3.

(a) Loss of acetyl-CoA carboxylase activity in the D6DCO2 mutant strain at restrictive growth temperature. Cell-free extracts were prepared from strains mc²155/pCG76 and D6DCO2 growing at 42 °C (−3, 2, and 4 h before or after D6DCO2 stopped growing), and acetyl-CoA carboxylase activity was determined for each sample as indicated in Methods. Results are the means of three independent experiments. (b) Determination of metabolic activity by incorporation of [³H]leucine. At different time points aliquots of mc²155/pCG76 and D6DCO2 cultures growing at 42 °C were labelled for 1 h with [³H]leucine and the radioactivity incorporated into the cells was measured as indicated in Methods. The results were normalized by OD₆₀₀ and are the means of three independent experiments.