Ribosomal frameshifting and transcriptional slippage: From genetic steganography and cryptography to adventitious use

Atkins, John F.; Loughran, Gary; Bhatt, Pramod R.; Firth, Andrew E.; Baranov, Pavel V.

Elaborate structures do not just involve pseudoknots. The bacterial transposable element IS911 stimulatory structure has a three-way junction and constituent stem loops (188, 194) . The 3 stem loop important for H. neapolitans carboxysome cso2 frameshifting is more complex (316) than its dnaX counterpart (517) , but there appears to be no 5 Shine Dalgarno stimulator in that case. (Just 2 substitutions in the E. coli dnaX stem loop can increase frameshifting to 176% of the WT level, so selection can readily yield the optimum efficiency.) While most work on bacterial mRNA structural stimulators has been done with stem loops, pseudoknots are also employed for productive frameshifting by bacterial ribosomes both −1 (146, 399) and +1 (153, 154) .