Use of polymerase chain reaction to identify a leucyl tRNA in Streptomyces coelicolor

Polymerase chain reaction (PCR) was used to amplify a fragment of DNA encoding a tRNA that recognizes the abundant CUC leucine codon from the chromosome of Streptomyces coelicolor. Sequence analysis of the gene, designated leuU, indicated that it codes for a tRNA 88 nucleotides in length that shares 75% identity with the Escherichia coli tRNA Leu CUC, while it shares only 65% identity with the only other sequenced leucyl tRNA from S. coelicolor, the bldA encoded tRNA Leu UUA. Accumulation of the leuU tRNA was examined by Northern blot analysis and shown to be present at constant levels throughout growth in contrast to the bldA-encoded tRNA which shows a temporal pattern of accumulation [ Leskiw et al., 1993. J. Bacteriol., 175, 1995–2005].