Figure 1

Promoter mapping of rhlG. A: Schematic representation of the rhlG locus. Black flags indicate the promoters P_AlgU, Pσ⁵⁴, and Pσ⁷⁰; and arrows indicate the rhlG and PA3388 genes. B: Annotated sequence of the rhlG promoter region. Black triangles indicate the three transcription start sites (+1) and the negative numbers provide their position relative to the rhlG translation initiation codon. The promoter sequences recognized by the sigma factors AlgU, σ⁵⁴, and σ⁷⁰ are respectively point over lined, full trait over lined, and underlined. The “lux box” as proposed in [4] is boxed with the two highly conserved dinucleotides underlined. The chromatograms show the results of 5′-RACE PCR allowing us to identify the major transcription start sites resulting from P_AlgU and the minor from 1 Pσ⁷⁰, the white arrow corresponding to the last base before the polyC tail added to the 5′ extremity of cDNA. The transcription start site resulting from Pσ⁵⁴ was identified in [4].