FIG. 3.

Determination of the transcriptional start sites for the S. meliloti orfA-pta-ackA-fabI operon by primer extension. RNA was purified from cells of wild-type strain 104A14 after incubation under high-phosphate culture conditions (Phos. +) or under phosphate starvation conditions (Phos. −). Lanes G, A, T, and C show the sequence ladders generated with the same primer as that used in the extension reaction, with pMLS7 as a template. Relevant complementary DNA sequence is shown on the right, and the positions of the start sites are indicated with asterisks.