Expression of the ssp4 gene and Ssp4 production by wild-type, ssp4 null mutants, and complementing strains of F4969 or SM101.
Panel A, RT-PCR analyses for ssp4 expression by SM101, SM101::ssp4, and complementing strains grown for 6 h in DS mediuim. Panel B, RT-PCR analyses of ssp4 expression by F4969, F4969::ssp4, and complementing strains grown for 6 h in DS medium. Lane 1 shows size markers. Lanes labeled “+” were from samples receiving reverse transcriptase, while lanes labeled “-“ lacked reverse transcriptase to show the absence of DNA contamination. Panel C, Western blot analyses for Ssp4 production by overnight DS cultures of wild-type, ssp4 null mutants or complementing strains of F4969 or SM101.