Figure 1.

Schematic representation of the different modes of action of transcriptional regulation by noncoding RNA. (a) Regulation by cis-encoded RNA, subdivided into signal-mediated folding or unfolding of the translation initiation region (top) or transcription termination/antitermination (bottom). (b) Regulation by antisense RNA (asRNA). (c) Regulation by trans-encoded sRNA. Circled P, promoter; circled S, environmental or metabolic signal.