FIG. 4.
(A) Stimulation of full-length transcription of the SLS (sag) operon probed with sagA in Northern hybridizations of RNA extracted from cells starved for isoleucine and valine [-(I+V)]. Control cells were grown in complete CDM (+AA). The indicated sizes of the hybridizing mRNA species are consistent with the map of the SLS operon shown in panel B.