Novel tRNA gene organization in the 16S-23S intergenic spacer of the Streptococcus pneumoniae rRNA gene cluster.

Isoleucine and alanine tRNAs are encoded tandemly within the 16S-23S intergenic spacer of some eubacterial rRNA gene clusters. Southern hybridization analysis and DNA sequence analysis demonstrated a novel gene organization for an rRNA gene cluster on the Streptococcus pneumoniae chromosome. A sequence specifying an alanine tRNA was found within the intergenic spacer, but no sequence specifying an isoleucine tRNA was found there. Southern hybridization analysis indicated that the location of the isoleucine tRNA gene was near the 5S rRNA gene in two of four rRNA gene clusters.