FIG 4.

(A) HPLC analysis of cmo⁵U levels of various E. coli peptidase U32 gene deletion mutants analyzed as described for Fig. 3A. The last two panels show the ΔyegQ ΔyhbUV ΔrlhA quadruple mutant without and with coinjection of cmo⁵U standard. The cmo⁵U peak was also isolated from this mutant and verified for identity by high-resolution mass spectrometry. (B) Quantitative analysis of selected gene deletions and complementation of E. coli peptidase U32 gene deletions based on HPLC analyzed levels of cmo⁵U in purified total tRNA. ***, P < 0.001 (unpaired t test) compared to wt strain.