FIG. 3.

Genetic organization of operons involved in sulfate assimilation or cysteine biosynthesis (A) and in methionine biosynthesis (B). A bent arrow indicates the experimental transcriptional start site. The potential −10 boxes for the promoters are underlined. The translational start codon is indicated in italics. The gray boxes correspond to conserved motifs. The terminators are represented by a loop. The positions of the primers used for the determination of the operon by RT-PCR are indicated by arrows.