A precursor molecule of species 1 RNA, p2Sp1, that accumulates when an rne (RNase E−) mutant is infected with a T4 deletion mutant (Δ27) is also found after infection of an rne host mutant by different deletion mutants or wild type bacteriophage T4. Low levels of this molecule were also found in a wild-type host infected with a wild-type T4. This precursor molecule accumulates at higher concentrations at 43°C as compared to 30°C or 37°C. Structural analysis of the precursor molecules from the different sources has shown a complete identity of p2Sp1 RNA isolated from the different sources. Therefore, we suggest that this precursor is a normal intermediate in processing of T4 tRNAs, and that it is unrelated to a particular T4 deletion strain. Since RNase E does not process this precursor, its accumulation in an rne mutant reflects an interaction between RNase E and the enzyme that processes this intermediate.
