FIG 5.

VapC1^NTHi and VapC2^NTHi cleave NTHi tRNA^fMets. (A) Sequence alignment of E. coli tRNA^fMet and NTHi tRNA^fMet-14 and tRNA^fMet-23. Sequence differences are highlighted in bold, and the anticodon sequence is underlined. (B) Differential hybridization Northern blot analysis of total RNAs isolated from E. coli BL21(DE3) cells expressing VapC toxins (induced with 0.01% l-arabinose) and tRNAs (induced with 0.5 mM IPTG) as indicated, performed as described in Materials and Methods. The blots were hybridized with an oligonucleotide specific to both E. coli tRNA^fMet and the NTHi tRNA^fMet of interest, but with one nucleotide mismatch for the E. coli tRNA^fMet. After hybridization of the probe, blots were washed at 42°C and then again at 68°C, as indicated above each panel.