In two recent articles by Nitta et al. (1998a,
1998b), evidence was presented that in vitro-transcribed
protein-free 23S rRNA of Escherichia coli (and
its individual domains) can catalyze peptide bond formation.
The implications of these studies are considerable because
demonstration of catalytic activity associated with protein-free
23S rRNA would be fundamental to our understanding of the
mechanism and evolution of protein synthesis (Noller et
al., 1992; Khaitovich et al., 1999).