Figure 6.

Mutations in nusG gene relieve chiP polarity. Mutants were obtained by combining random PCR mutagenesis and chromosomal recombineering as described in the text. (A) Effect of nusG mutations on the expression of chiQ-lacZ in a chiP_AGG mutant background. Strains used were MA11167 (nusG^wt), MA11158 (nusG 174fs), MA11159 (nusG F144I), MA11161 (nusG V162D), and MA11162 (nusG F141S). (B) Effect of nusG mutations on the synthesis of S. aureus tRNA (see the legend for Fig. 2D). Total RNA extracted from stationary cultures was processed for Northern blotting as in Figure 2D. The blot was hybridized to an oligonucleotide complementary to tRNA^S.a (ppJ62). Strains used were MA11170 (nusG^wt), MA11171 (nusG 174fs), MA11172 (nusG 144I), and MA11173 (nusG V162D).