The name of these structures was first applied to an element in E. coli’s rpoH gene, whose translation yields the sigma-32 factor. For 10 points each:
[10h] Name these structures that are analogous to riboswitches, but rely on a different stimulus than ligand binding to exert their effects. The agsA gene found in Salmonella enterica contains one of these structures called FourU.
ANSWER: RNA thermometers [or RNA thermosensors]
[10m] The hairpins in prokaryotic (“pro-care-ee-AH-tick”) RNA thermometers often preclude access to these sites to inhibit base-pairing between them and the 16S subunit. High temperatures melt the hairpin to expose these sites, enabling translation.
ANSWER: Shine–Dalgarno sequences [or Shine–Dalgarno boxes; accept ribosome-binding sites or RBS]
[10e] Most RNA thermometers are located in the 5-prime UTRs of mRNAs that encode this set of chaperones. agsA codes for one of these proteins, which respond to both heavy metal damage and cold, despite their name.
ANSWER: heat shock proteins [or HSPs]
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