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.

Highlighting the contrast between the IBV and MMTV gag-pro type pseudoknots just considered, a functionally inactive mutant of the former with 6 bps in stem 1 and 8 nts in loop 2 could be converted to the counterpart of an active MMTV gag-pro pseudoknot by addition of an unpaired and presumably intercalated adenosine at the heli-cal junction, and an adenosine in the 3 terminal position of loop 2 (540) . The efficiency of the infectious bronchitis virus pseudoknot with its long stem 1, is unrelated to the thermodynamic stability (106) or its mechanical unwinding properties (541) . The first cryoEM studies of ribosomal response to a frameshift stimulatory pseudoknot utilized the avian infectious bronchitis virus pseudoknot and revealed distorted tRNAs in two different A/P hybrid states (108, 542) . The more recent major improvements in cryoEM sensitivity means that invaluable insights will be forthcoming.