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.

Though the stop codon 3 adjacent to the take-off codon in gene 60 mRNA is an important feature of bypassing at normal concentrations of release factor, it does not compete to mediate termination. The efficiency of take-off is very high (451, 483, 488) . However, some ribosome dropoff does occur before retained ribosomes resume decoding (451, 489) . The anticodon of peptidyl-tRNA retained within the ribosome during bypassing does not scan at least the first half of the coding gap (385) , but does appear to scan near the site of its re-pairing to mRNA at a matched GGA codon -the landing site (451) . Pairing of a minimal internal Shine Dalgarno sequence 6 nts 5 of the landing site with its rRNA complement in bypassing ribosomes has a modest effect on landing site selection (385) prior to coding resumption at the adjacent codon (a similar function for a Shine Dalgarno sequence has been proposed for the likely Streptomyces phage bypassing (161) though it is 5 of the start of the much shorter coding gap).