Figure 1.

Nucleotide sequence of the divergent promoter region of the ilvYC operon in pSAE1. Base pair positions from +6 to −60 relative to the ilvC transcriptional start site are shown (6). The transcription start sites for ilvY and ilvC are identified by arrows. The −10 and −35 hexanucleotide regions of the ilvY (bottom strand) and ilvC (top strand) promoters are identified with horizontal lines. The O₁ (truncated) and O₂ operator sites are denoted by brackets. The mutated bases in the ilvC promoter contained in pSAE2 and in the ilvY promoter contained in pSAE3 are identified by dashed lines and bold characters.