Chapter 13. Regulatory RNA. 13.1 Introduction. RNA functions as a regulator by forming a region of secondary structure (either inter- or intramolecular) that changes the properties of a target sequence. Figure 13.1: Regulator RNA binds RNA target.
Figure 13.1: Regulator RNA binds RNA target.
Figure 13.2: Termination occurs when hairpin forms.
Figure 13.3: TRAP controls the B. subtilis trp operon.
Figure 13.4: Anti-TRAP is controlled by tRNATrp.
Figure 13.5: Termination can be controlled via changes in RNA secondary structure that are determined by ribosome movement.
Figure 13.6: Transcription is controlled by translation.
Figure 13.7: The control region of the trp operon codes for a leader peptide.
Figure 13.8: Alternative secondary structures control termination.
Figure 13.9: Tryptophan controls ribosome position.
Figure 13.10: Trp-tRNA controls the E. coli trp operon directly.
Figure 13.11: GlcN6P activates a ribozyme that cleaves the mRNA.
Figure 13.13: A 3' terminal loop in oxyS RNA pairs with the initiation site of flhA nRNA.
Figure 13.14: PHO84 antisense RNA stabilization is paralleled by histone deacetylase recruitment, histone deacetylation and PHO84 transcription. Under normal conditions, the RNA is rapidly degraded. In aging cells, antisense transcripts are stabilized and recruit the histone deactylase to repress transcription.
Figure 13.15: lin4 RNA regulates expression of lin14 by binding to the 3’ nontranslated region.
Long dsRNA inhibits protein synthesis and triggers degradation of all mRNA in mammalian cells, as well as having sequence-specific effects. Short dsRNA (<26nt) leads to degradation of only complementary mRNAs.