Evolution of protein synthesis from an RNA world.
Because of the molecular complexity of the ribosome and protein synthesis, it is a challenge to imagine how translation could have evolved from a primitive RNA World. Two specific suggestions are made here to help to address this, involving separate evolution of the peptidyl transferase and decoding functions. First, it is proposed that translation originally arose not to synthesize functional proteins, but to provide simple (perhaps random) peptides that bound to RNA, increasing its available structure space, and therefore its functional capabilities. Second, it is proposed that the decoding site of the ribosome evolved from a mechanism for duplication of RNA. This process involved homodimeric "duplicator RNAs," resembling the anticodon arms of tRNAs, which directed ligation of trinucleotides in response to an RNA template.
Noller
Harry F
HF
Center for Molecular Biology of RNA and Department of Molecular, Cell, and Developmental Biology, Sinsheimer Laboratories, University of California at Santa Cruz, Santa Cruz, California 95064, USA. harry@nuvolari.ucsc.edu
D005075:Biological Evolution; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D012313:RNA / Q000737:chemistry / Q000235:genetics
D012313:RNA