Deletion analysis of the expression of rRNA genes and associated tRNA genes carried by a lambda transducing bacteriophage.

Transducing phage lambdailv5 carries genes for rRNA's, spacer tRNA's (tRNA1 Ile and tRNA1B Ala), and two other tRNA's (TRNA1 Asp and tRNA Trp). We have isolated a mutant of lambdailv5, lambdailv5su7, which carries an amber suppressor mutation in the tRNA Trp gene. A series of deletion mutants were isolated from the lambdailv5su7 phage. Genetic and biochemical analyses of these deletion mutants have confirmed our previous conclusion (E. A. Morgan, T. Ikemura, L. Lindahl, A. M. Fallon, and M. Nomura, Cell 13:335--344, 1978) that the genes for tRNA1 Asp and tRNA Trp located at the distal end of the rRNA operon (rrnC) are cotranscribed with other rRNA genes in that operon. In addition, these deletions were used to define roughly the physical location of the promoter(s) of the rRNA operon carried by the lambdailv5su7 transducing phage.