FIG. 1.

Genomic structure of the ram cluster. The arrows indicate the ram genes. ramC encodes a membrane-bound serine/threonine kinase, ramS encodes a small protein with unknown function, ramA and ramB are translationally coupled and encode components of an ABC transporter, and ramR encodes a response regulator. P1, P2, and P3 mark the promoter regions involved in transcription of the ramCSAB genes, while Pr marks the ramR promoter. The symbol ⊥ downstream of ramS marks the position of a transcriptional terminator. Below the map are indicated the DNA probes used in high-resolution nuclease S1 protection assays. The asterisks represent the ³²P-labeled end. The horizontal lines indicate homologous regions, while the diagonal parts indicate the nonhomologous parts of the probe (usually derived from cloning vector pTZ19R).