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.

Any particular case of programmed frameshifting is generally specific in terms of directionality, though there are some evolutionarily conserved exceptions (e.g. the tailed double-stranded DNA phages where either −1, −2 or +1 is used in different phages to yield a ratio of two products important for tail length and assembly (40, 41, 48, 49) . Most known instances of ribosomal frameshifting mediating access to the +1 frame are by +1 frameshifting, but −2 frameshifting is known and results in specification of an additional amino acid compared to +1 frameshifting. −2 frameshifting is used in decoding phage Mu (50, 51) , arteriviruses (nsp2TF), including an important pig pathogen where the efficiency is 20% (22) and Trichomonas vaginalis virus-1, a virus that infects an important human genitourinary protozoan parasite (52) , perhaps with the nature of potential frameshifting in its host Trichomonas (53) being relevant. [However, Trichomonas vaginalis virus-2, -3 and -4 all utilize −1 frameshifting instead of −2.]