ERRORS IN THE CENTRAL DOGMA

Evolution requires errors - the source of variation, upon which selection acts. Predominantly, mutations in genotype copying are considered the main source of such variation. Yet phenotypic errors, ie errors in the execution of the genetic material, abound too and may provide a constant source of variation. So far we were lacking reliable experimental method to detect and quantity phenotypic errors. In bacterial populations such errors could endow isogenic lines with functional variability and non genetic individuality.

Here I’ll describe the first method to measure error in protein translation at the amino acid resolution from proteome mass spec in E. coli and yeast. Our measurements reveal rules that govern where and when the translation machinery makes errors. We find that errors are controlled and even programmed to occur in sites that also evolve more rapidly by DNA mutations. Physiological conditions such as amino acid starvation and antibiotics affect the error patterns and reveal particular sites of phenotypic variability. Together this new method reveal a new layer of physiological and environmental regulation of the bacterial proteome.