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Molecular basis for temperature sensing by an RNA thermometer
Author(s) -
Chowdhury Saheli,
Maris Christophe,
Allain Frédéric HT,
Narberhaus Franz
Publication year - 2006
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7601128
Subject(s) - rna , biology , riboswitch , ribosome , helix (gastropod) , biophysics , non coding rna , translation (biology) , nucleic acid structure , ribosomal binding site , microbiology and biotechnology , messenger rna , genetics , gene , ecology , snail
Regulatory RNA elements, like riboswitches, respond to intracellular signals by three‐dimensional (3D) conformational changes. RNA thermometers employ a similar strategy to sense temperature changes in the cell and regulate the translational machinery. We present here the first 3D NMR structure of the functional domain of a highly conserved bacterial RNA thermometer containing the ribosome binding site that remains occluded at normal temperatures (30°C). We identified a region adjacent to the Shine–Dalgarno sequence that has a network of weak hydrogen bonds within the RNA helix. With the onset of heat shock at 42°C, destabilisation of the RNA structure initiates at this region and favours the release of the ribosome binding site and of the start codon. Deletion of a highly conserved G residue leads to the formation of a stable regular RNA helix that loses thermosensing ability. Our results indicate that RNA thermometers are able to sense temperature changes without the aid of accessory factors.