THE BLDA-ENCODED TRANSFER-RNA IS POORLY EXPRESSED IN THE BLDL MUTANT OF STREPTOMYCES-COELICOLOR A3(2)

The bldA gene, encoding a leucyl tRNA recognizing the UUA codon, is expressed at significantly lower levels in the bldI mutant, Streptomyces coelicolor J703, than in the parent S. coelicolor A3(2). Expression of a TTA-containing reporter gene was reduced in the bldI mutant, as was the mature, 87 nucleotide, form of the bldA-encoded tRNA. This reduced level of the tRNA was also seen when the bldA gene was introduced on a high-copy-number plasmid into the bldI mutant, suggesting that maximal bldA expression may require a bldI-dependent promoter.