Figure 3

trpX is part of an operon. (a) Identification of the trpX transcriptional start site (TSS) by 5′ RACE. Alignment of the genomic region upstream of trpX with clones obtained by 5′ RACE from one representative out of two experiments. Prediction of regulatory elements is highlighted in red. The position of the identified TSS (+ 1) is indicated by an arrow. Dots indicate nonmatching nucleotides. (b) Genomic organization of trpX to trpZ and illustration of possible amplification products with the indicated primer pairs (solid blue lines), scheme not true to scale. (c) Corresponding representative agarose gels. NTC non-template control, cDNA standard RT-PCR reaction using reverse transcribed RNA, −RT negative control in which no reverse transcriptase was added to the RT reaction, gDNA positive control in which genomic DNA was used as a template in the RT-PCR. Left [1] and right [2] gel show the products obtained with GSP_II_rev and TrpX_1_for and TrpZ_rev and TrpX_for, respectively as depicted in panel (b). Original gels are presented in Suppl. Fig. S2 online.