FIG 1.

Generation of dpr mutants. (A) Schematic diagram of the generation of the dpr mutants and revertants using a bicistronic (Janus) cassette. Black arrows indicate the position of primers for reverse transcription-PCR in Fig. 1B. (B) dpr, dhfr, and clpX are in a single transcript. RNA was extracted from pneumococcal TIGR4 and 603 strains, and cDNA was generated by reverse transcription. PCR products using cDNA (top) or RNA (bottom) were amplified using primers listed in Table 1. (C) PCR amplification of genomic DNA from revertant and KO strains using two outside primers. (D) Western blotting was performed to confirm the phenotypes of the dpr KO and revertant strains in the 603 strain background. Pneumolysin was used as a loading control.