Subcellular localization of enzymes in Streptomyces aureofaciens and its alteration by benzyl thiocyanate. I. Phosphatases and ATP-glucokinase

Protein profiles of Streptomyces aureofaciens producing tetracyclines: reappraisal of the effect of benzyl thiocyanate

Cell protein profiles of submerged cultures of Streptomyces aureofaciens cultivated in the absence or presence of 12 microM benzyl thiocyanate (BT) were analyzed by one-dimensional SDS polyacrylamide gel electrophoresis. Substantial increase in the intensity of the 13, 35, 37, 60, and 100 kDa protein bands was observed in cultures treated with BT. Similar increase in the 35, 37, and 60 kDa bands was found in a mutant blocked in the last chlortetracycline biosynthesis step. Effect of BT on the solid medium-grown cultures was also observed, with a more intensive substrate mycelium pigmentation and alteration in the spore size and shape as the most characteristic features. Earlier studies of BT effect involving those on the stimulation of chlortetracycline biosynthesis are summarized and a possible signal-transducing mechanism is discussed from the point of view of adaptation of S. aureofaciens to the uncoupling of oxidative phosphorylation.

Subcellular localization of enzymes in Streptomyces aureofaciens and its alteration by benzyl thiocyanate. II. Anhydrotetracycline oxygenase and glucose-6-phosphate dehydrogenase

The localization of anhydrotetracycline oxygenase and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) was studied by determining the enzyme activities in subcellular fractions obtained by differential centrifugation of the mycelia of Streptomyces aureofaciens after lysozyme treatment. Glucose-6-phosphate dehydrogenase was a typical cytoplasmic enzyme both in the low- and high-production strain. Anhydrotetracycline oxygenase was found in the membrane fraction of the low-production strain. In the high-production strain, it was detected in several fractions, the highest activity being found in cytoplasm. The presence of 10 microM benzyl thiocyanate in the culture medium significantly changed the distribution of the latter enzyme in both strains. The redistribution of the enzymes is discussed with respect to tetracycline over-production.