CCRA1 - A MUTATION IN STREPTOMYCES-COELICOLOR THAT AFFECTS THE CONTROL OF CATABOLITE REPRESSION

The regulation of carbon utilization is of central importance in the g ene expression pathways for both morphological development and antibio tic production in Streptomyces species. We report the identification a nd characterization of a mutation in Streptomyces coelicolor, ccrA1, t hat affects the expression of several catabolite-controlled promoters. ccrA1 mutants are altered in expression of galP1, the glucose-sensiti ve, galactose-dependent promoter of the galactose utilization operon; in expression of the glycerol utilization operon, which is glucose sen sitive and glycerol dependent; and in expression of chi63, the glucose -sensitive chitin-dependent promoter of a gene involved in chitin util ization. ccrA1 has no effect on the expression of galP2, a promoter th at directs constitutive transcription of the galE and galK genes. ccrA 1 maps to a region of the S. coelicolor genome which distinguishes it from other mutations known to be involved in catabolite control. We su ggest that ccrA1 identifies a gene whose product may be involved in th e general regulation of carbon catabolite repression in this complex b acterium.