English: Nine of the ten most ancestral folds identified by Wang et al. [26] are present in translation proteins. The specific functional roles of these folds converge on four general categories: high energy phos- phoryl transfer, RNA modification, RNA binding, and protein binding. Exceptions are aminoacylation by tRNA synthetase and tRNA splicing by ribo- somal protein S28e. Taken together, the functions imparted by these nine most ancestral folds represent all of the central protein functions in the modern translation system (Figure 4). A summary of the genes in which these folds are found is available as Additional file 2. A detailed annotation of functions imparted by these folds is available as Additional file 3.^[1]