FIG 4.

Expression of the genes furA and furB. C. metallidurans strain AE104 and its ΔrpoI deletion mutant that is unable to produce staphyloferrin B were treated for 10 min with 500 μM Fe(III) (B, lanes 1 and 5), 100 μM Fe(III) (A, lanes 1 and 4; B, lanes 2 and 6), 80 μM DIP (A, lanes 2 and 5; B, lanes 3 and 7), or without additions (A, lane 3; B, lanes 4 and 8). RNA was isolated, treated with DNase I, and reverse transcribed with random hexameric primers, and the cDNA subsequently was amplified by PCR using furA (A)- or furB (B)-specific primers. M, marker lane with two bands labeled. Lanes 6 and 9 in panels A and B, respectively, show the negative control (no template control). Lanes 7 and 10 in panels A and B, respectively, show the positive control (genomic DNA instead of RNA). As a loading control, the constitutively expressed gene rpoZ was amplified by PCR showing the same amounts of product for all RNA samples.