The maintenance of the accuracy of protein synthesis and its relevance to ageing: a correction.

Abstract

An argument1 purporting to show that the accuracy of protein synthesis would deteriorate in the absence of cellular selection, thus leading to an catastrophe, contains a hidden assumption that no longer seems justified. I supposed that the error frequency in protein synthesis could be approximated as the sum of a residual error frequency (applicable where the protein-synthetic apparatus contains no errors) and a term dependent linearly on the number of errors already present in the protein-synthetic apparatus. I deduced that the error frequency would increase exponentially. To clarify the nature of the hidden assumption I now consider a simpler model in which successive generations of the protein-synthetic apparatus are discrete and distinguishable. Let c, be the error frequency in the nth generation, R the residual error frequency, and a the proportionality constant between errors in the synthetic apparatus and errors in freshly synthesized protein. Then