title: Beta-turn-driven early evolution: the genetic code and biosynthetic pathways.
abstract: The physicochemical properties of beta-turns suggest their biological importance prior to the formation of the genetic code. These properties include ones potentially affecting the preference for either L- or D-amino acids. The abundance of certain amino acids in beta-turns is correlated with their assignment to a small, well-defined part of the genetic code and with their role as metabolic precursors for other amino acids. It is proposed that in the prebiotic environment, beta-turns became objects of selection that influenced the evolution of the genetic code and biosynthetic pathways for amino acids.
mesh_terms: D005075:Biological Evolution; D003062:Codon; D004355:Drug Stability; D005815:Genetic Code; D008957:Models, Genetic; D011487:Protein Conformation
chemical_list: D003062:Codon