The 5′-untranslated regions and the first 10 codons of BAB1_0314, BAB2_0879, or BAB2_0612 were cloned in-framed with gfp into a low-copy plasmid, and abcR1, abcR2, or a DNA fragment encoding a nonsense sRNA (the abcR2 gene in reverse) were cloned into a high-copy plasmid (see Experimental procedures). E. coli strains carrying only a gfp fusion construct, or carrying both a gfp fusion construct and a sRNA-encoding construct, were grown in LB broth, and immunoblot analyses were performed on total protein lysates to detect levels of GFP or GroEL.