FIG 6.

16S rRNA-mRNA complementarity is required for growth of the spontaneous mutants. (A) Growth was tested on GM17 plates incubated for 36 h at 37°C. In three of the spontaneous mutants, the unique nucleotide of the mutation was changed to two other nucleotides. Each site-directed fabK gene was cloned into the vector pTRKL2 and then transformed to the ΔfabI strain, FAZL1. (B) Effects of the nucleotide changes on β-galactosidase expression from a plasmid carrying a P32::fabK::lacZ translational fusion. The wild-type strain FA2-2 carrying the fusion plasmids was grown in GM17 medium to mid-log phase, and β-galactosidase activities were measured from more than three independent experiments. The error bars indicate standard deviations. The designations p(WT), A-9T, A-9C, C-12A, C-12T, T-19A, T-19C, and p(S4) indicate the fusion plasmids pBHK323, pBHK334, pBHK335, pBHK336, pBHK337, pBHK338, pBHK339, and pBHK327, respectively. The p(WT) and p(S4) plasmids were used as negative and positive controls, respectively.