Programmed +1 Translational Frameshifting in the Yeast Saccharomyces cerevisiae Results from Disruption of Translational Error Correction

A commonly held belief, especially among beginningstudents of molecular biology, is that the process of protein synthesis is faithful—the sequence of codons in anmRNA defines exactly the sequence of amino acids in theencoded protein. Of course, like any biological process,protein synthesis is inherently error-prone. Nevertheless,it is important that translation is as nearly faithful as possible to avoid disastrous translational errors. However,increasing accuracy can also be counterproductive; despite the fact that slower translation is more accurate, decreasing the rate of translation can actually limit growth(for review, see Kurland et al. 1996). Therefore, thetranslational machinery has been subject to opposing selections: to translate rapidly in order to produce more protein, and to translate accurately in order to produceproducts more faithfully (Kurland et al. 1996). The compromise results in an average of 5 x 10-4 missense errorsand fewer than 3 x 10-5 frameshift errors per codon translated (Kurland 1979; Parker 1989)...