Genetic map and operon structure of VPA0148VPA0156 locus.

(A) Genetic map of the peuA gene and the flanking genes. Thick arrows indicate genes and their orientations. The –35 and –10 promoter elements and putative Fur box sequences in the promoter regions of peuR (VPA0148) and peuA (VPA0150) are indicated. The transcription start sites for peuR (+1) and peuA (+1 and +39) are indicated by right-angled arrows. The putative terminator signal between the peuS and peuA genes, the predicted RBS for the peuA gene, the start codons for peuR and peuA genes, and the stop codon for peuS are also indicated. The amino acid sequence consistent with the N-terminal sequence determined for the iron-repressible OMR induced in LB-Tris/+EDDA and LB-Tris/+EDDA/+Ent media at pH 8.0 (see Figure 3) is indicated by a double underline. (B) Schematic representation of mRNAs transcribed from the VPA0148-VPA0156 genes and the primer pairs used for RT-PCR. For preparation of cDNAs by RT, VPpeuS-R and VP0156-R were used. (C) RT-PCR analysis of RT-PCR products. +RT and –RT, RT-PCR was performed with and without reverse transcriptase, respectively. M, 100-bp DNA ladder.