Professor Dr. Andrei Lupas (Universität Tübingen)
in: 'Frontiers in Ecology and Evolution': "On the Origin of Life: Major hurdles on the path from organic chemistry to biochemistry"
by Professor Dr. Andrei Lupas (Universität Tübingen)
Based on the inferred planetary conditions on early Earth, Life is thought to have started around 3.8 to 4 billion years ago. Molecular phylogenies further suggest that the first major split of lineages from the Last Universal Common Ancestor occurred some 3.5 billion years ago, at which time we already had biochemically modern cells with a lipid plasma membrane, a universal genetic code supported by a fully formed transcription and translation apparatus, a comprehensive core metabolism, and prototypes for all the main families of folded proteins. Here we will review the obstacles that Life most likely encountered in its progress over half a billion years, from a network of prebiotic reactions to the fully formed DNA-protein world that we still observe today. An important focus will be on the last hurdle, the protein folding problem, which had to be overcome at the transition from an RNA-peptide to the DNA-protein world.