Glycerol catabolic enzymes and their regulation in wild-type and mutant strains of Streptomyces coelicolor A3(2).
Assay procedure were developed for a soluble glycerol kinase (apparent Km (glycerol) 9 microM) and a probably membrane-associated, NAD-independent L-glycerol-3-phosphate dehydrogenase [apparent Km (L-glycerol 3-phosphate) 7 mM] present in Streptomyces coelicolor A3(2). Both enzymes were cold sensitive. They were co-ordinately induced (about 35-fold) by addition of glycerol to cultures growing on arabinose as sole carbon source. Induction was rifampicin sensitive. The dehydrogenase was absent from glycerol-sensitive mutants, and both kinase and dehydrogenase were absent from glycerol non-utilizing (but glycerol-resistant) mutants, demonstrating that the two enzymes are part of the major pathway of glycerol catabolism in S. coelicolor. Circumstantial evidence suggested that their inducer is glycerol 3-phosphate rather than glycerol. The enzymes were subject to co-ordinate repression by various carbon sources, of which glucose exerted the strongest effect (a fivefold repression). Previously described mutants resistant to 2-deoxyglucose, shown here to have very low glucose kinase activity, were defective in glucose repression of the glycerol enzymes.
D004790:Enzyme Induction / Q000187:drug effects; D005786:Gene Expression Regulation; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism* / Q000494:pharmacology; D005991:Glycerol Kinase / Q000032:analysis / Q000096:biosynthesis; D050536:Glycerol-3-Phosphate Dehydrogenase (NAD+); D005993:Glycerolphosphate Dehydrogenase / Q000032:analysis / Q000096:biosynthesis; D009154:Mutation; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics
D005993:Glycerolphosphate Dehydrogenase; D050536:Glycerol-3-Phosphate Dehydrogenase (NAD+); D005991:Glycerol Kinase; D005947:Glucose; D005990:Glycerol