FIG 1.

Transcription of genes in the hrpB operon. (A) Graphic representation of the hrpB operon and RT-PCR products amplified using primers designed to span intergenic junctions. Arrows shaded in gray represent hrpB1 (B1), hrpB2 (B2), hrcJ (J), hrpB4 (B4), hrpB5 (B5), hrcN (N), and hrpB7 (B7). The black arrow represents hrcT (T), and the open white arrow depicts hrcC (C). The black rectangle adjacent to hrpB1 represents the hrpB operon promoter, and the black triangle indicates the insertion of the Gm cassette in opposition to the hrpB operon promoter (mutant RΔBP). The black lines indicate the sizes of RT-PCR products amplified using the intergenic primers (see Table S1 in the supplemental material). The dashed lines indicate that no RT-PCR products were generated in the mutant RΔBP. (B) RT-PCR products detected by agarose gel electrophoresis. Abbreviations: WT, cDNA from wild-type RS105; RΔBP, cDNA from the mutant in the hrpB operon promoter; WT gDNA, genomic DNA from wild-type RS105; NC, the extracted RNAs were used for PCR to ensure no residual genomic DNA in samples; M1, DL5000 DNA ladder (TaKaRa); M2, DL2000 DNA ladder (TaKaRa). 16S rRNA was used as an internal control to verify cDNA levels.