mRNA bound to the 30S subunit is a HigB toxin substrate

HigB cleaves mRNA bound to the 30S subunit. (A) Schematic of in vitro cleavage assays performed on the E. coli 30S ribosomal subunit with 30S domains labeled. (B) E. coli 30S was programmed with ³²P-labeled 25-mer mRNA containing an A-site 5′-AAA-3′ lysine codon, P-site tRNA^fMet, and HigB toxin, and mRNA cleavage was monitored over 60 min. Solid arrow indicates uncleaved mRNA, open arrow indicates the cleaved mRNA product, and 19-mer, 20-mer, and 21-mer standards are shown to the left.