Open AccessA trans-acting RNA as a control switch in Escherichia coli : DsrA modulates function by forming alternative structures
Author(s) -
Richard A. Lease,
Marlene Belfort
Publication year - 2000
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.170281497
Subject(s) - rpos , rna , biology , genetics , sigma factor , non coding rna , footprinting , nucleic acid structure , translation (biology) , transcription (linguistics) , messenger rna , gene expression , gene , rna polymerase , promoter , transcription factor , linguistics , philosophy
DsrA is an 87-nucleotide regulatory RNA ofEscherichia coli that acts in trans by RNA–RNA interactions with two different mRNAs,hns andrpo S. DsrA has opposite effects on these transcriptional regulators. H-NS levels decrease, whereas RpoS (σs ) levels increase. Here we show that DsrA enhanceshns mRNA turnover yet stabilizesrpo S mRNA, either directly or via effects on translation. Computational and RNA footprinting approaches led to a refined structure for DsrA, and a model in which DsrA interacts with thehns mRNA start and stop codon regions to form a coaxial stack. Analogous bipartite interactions exist in eukaryotes, albeit with different regulatory consequences. In contrast, DsrA base pairs in discrete fashion with therpo S RNA translational operator. Thus, different structural configurations for DsrA lead to opposite regulatory consequences for target RNAs.