Relative cat mRNA levels in pRIM2::promoter-carrying C. glutamicum CR031 strains compared to the corresponding C. glutamicum CR032 strains. Strains CR031-035i to CR031-048i and CR032-035i to CR032-048i carrying different promoter fragments cloned in pRIM2 in front of a promoterless cat gene were grown in MMS minimal medium with limiting amounts of sulphur. Details of the A, B, Am5 or Am3 form of the cloned promoter fragments are shown in Fig. 4. After 30 min sulphur starvation, cells were harvested, total RNA was isolated, and the relative cat mRNA amounts were determined using real-time RT-PCR. The values are the means of at least two independent biological samples with two technical replicates each.