EXPRESSION OF THE STREPTOMYCES-AUREOFACIENS GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE GENE (GAP) IS DEVELOPMENTALLY-REGULATED AND INDUCED BYGLUCOSE

In previous experiments, the Streptomyces aureofaciens gap gene encodi ng glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was identified. To investigate expression of the gene, S1 nuclease mapping and Northern blot hybridization were performed using RNA prepared from S. aureofaci ens cultivated under various conditions. These studies suggested monoc istronic organization and developmental regulation of the gene. A sing le promoter, gap-P, was identified upstream of the gap coding region. In cultures grown on solid medium in the absence of glucose, its trans cription was induced at the time of aerial mycelium formation. In addi tion, gap transcription was also induced in substrate mycelium by gluc ose. A promoter-bearing DNA fragment was inserted into two promoter-pr obe vectors, to give expression patterns consistent with the results o f direct RNA analysis.