2002 Volume 16 Issue 2 Pages 32-36
We found novel relC (=rplK) mutants from the Streptomyces coelicolor A3(2) strain. The mutant strains displayed a point mutation or a deletion mutation within the rplK gene, which codes for the ribosomal L11 protein. These relC mutants exhibited a markedly reduced ability to accumulate ppGpp upon nutritional shift-down and showed an inability to produce the antibiotic actinorhodin, although the mutants grew as well as the parental strain. Gene replacement experiments revealed that the relC mutation alone is responsible for this impaired ability to produce actinorhodin. This failure to produce the actinorhodin phenotype is conditional, as the relC mutants were capable of producing actinorhodin when cultured on plates containing a limited amount of phosphate.
