FIG. 2.
(A) Genetic organization of ers, EF_0082, EF_1459, and ADI and citrate operon chromosomal regions of E. faecalis V583. Large arrows indicate the different ORFs and their orientations show the transcriptional direction. Gene members of the Ers regulon are in black. The known or possible locations of the promoter regions (P) of those loci are indicated with bent arrows. Arrowheads indicate mutation sites by insertion of the pORI19-1 plasmid (see Materials and Methods for details). (B) Identification of the putative promoter region by RT-PCR experiments. PCRs using primers symbolized by black arrowheads in panel A were realized with cDNA (odd-numbered lanes) or chromosomal DNA (even-numbered lanes) matrices of E. faecalis JH2-2. The absence of amplification using the cDNA (lanes 1, 3, and 7) suggested that a putative promoter is located between the two primers used.