KnotInFrame: prediction of -1 ribosomal frameshift events

Theis, Corinna; Reeder, Jens; Giegerich, Robert

Programmed ribosomal frameshift (PRF), examined in this work, alters the reading frame by shifting the ribosome exactly 1 nt to either the +1 or À1 direction. A stop codon in the original reading frame is then bypassed in the shifted reading frame. This way, two different protein products can be obtained from one mRNA. The frequency of frameshifting events at a particular site is used by viruses for a defined ratio between the two proteins. Changes in the ratio can lead to less efficient virus propagation and thus, can be a target for antiviral therapeutics. Recently, a role of À1 PRF in posttranscriptional regulation has been proposed in Saccharomyces cerevisiae (5) . The authors propose a model where À1 PRF leads to premature termination targeting the mRNA for rapid degradation via the nonsense-mediated mRNA decay pathway.