The meaning of a minuscule ribozyme.

The smallest ribozyme that carries out a complex group transfer is the sequence GUGGC-3', acting to aminoacylate GCCU-3' (and host a manifold of further reactions) in the presence of substrate PheAMP. Here, I describe the enzymatic rate, the characterization of about 20 aminoacyl-RNA and peptidyl-RNA products and the pathways of these GUGGC/GCCU reactions. Finally, the topic is evolution, and the potential implications of these data for the advent of translation itself.