FIG. 4.

Promoter identification by primer extension. Total RNA was obtained from uninduced and mitomycin C-induced X. nematophila cells. Each reaction mixture contained 40 μg RNA. Lane 1, radiolabeled φX174 DNA marker; lanes 2 and 3, PriIm primer from the N′ terminus of the ximB gene with RNA from uninduced and induced cells, respectively; lanes 4 and 5, PriXc primer from the N′ terminus of the xcinA gene with RNA from uninduced and induced cells, respectively.