Regulation of various fusions by MicA

Copyright information:Taken from "Translational control and target recognition by small RNAs "Nucleic Acids Research 2007;35(3):1018-1037.Published online 30 Jan 2007PMCID:PMC1807950.© 2007 The Author(s). () Structure of the leader adapted from (). Nucleotides that pair with MicA are indicated by black boxes. The 5′ ends of the two truncated fusion, -30 and -95, are circled. () Introduction of compensatory base pair changes into MicA sRNA, yielding MicA_M6, restored regulation of the mutated M6 fusion mRNA, thus confirming specific pairing of the two RNAs . The M6 mutation in or MicA simultaneously disrupts base pairing between and MicA at six positions, as described previously (). strains carrying the wild-type or M6 mutant fusion plasmid were combined with a control plasmid (no sRNA expression), or the MicA or MicAM6 expression plasmids. Samples were taken at an OD of 1, and subjected to western (upper panel) and northern (lower two panels) blot analysis as in . () Effects of 5′ truncations on fusion mRNA stability and regulation by MicA. In the wild-type fusion (constructed by 5′ RACE cloning, see text), transcription from the constitutive P promoter starts at the native +1 site. Destruction of the terminal stem–loop of the leader neither affects stability or translation of the mutant fusion -95, nor its repression by MicA. However, further shortening of the leader as in mutant -30, which is deprived of both stem–loops, results in partial degradation of the fusion mRNA and loss of fusion protein translation. Samples were taken and probed as in (B).