FIG. 5.

Northern blot transcript analysis of the serotype M49 GAS strain CS101 (wild type [wt]) and an isogenic strain expressing a nisin-inducible pel gene. mRNA probes used were pel (A) and emm, M protein (B). Total cellular RNA was isolated from each strain in late logarithmic growth phase after exposure to nisin. RNAs were separated by MOPS-formaldehyde agarose gel electrophoresis. The source of the RNA is shown above the lanes, and the amount of RNA loaded is shown below the corresponding lanes. Uniform loading of the gel was confirmed after electrophoresis by visual inspection of the ethidium bromide-stained RNA. The approximate sizes of the molecular weight markers are shown on the right. The results shown are representative of those from at least two independent RNA isolations.