Small genomes and the difficulty to define minimal translation and metabolic machineries

The notion of minimal life has sparked the interest of scientists in different fields, ranging from the origin-of-life research to biotechnology-oriented synthetic biology. Whether the interest is focused on the emergence of protocells out of prebiotic systems or the design of a cell chassis ready to incorporate new devices and functions, proposing minimal combinations of genes for life is not a trivial task. Using comparative genomics and biochemistry of endosymbionts (i.e., intracellular mutualistic symbionts) and intracellular parasites, a decade ago we proposed the core of a minimal gene set for a simple heterotrophic cell adapted to a chemically complex environment. In this work, we di…