Reconstitution of Peptide Bond Formation with Escherichia coli 23S

It was recently demonstrated that peptide bond formation can occur using an Escherichia coli naked 23S ribosomal RNA without any of the ribosomal pro-teins. Here, the six domains of the 23S ribosomal RNA were individually synthesized and shown to be capable, when complexed together, of stimulating the reaction. Omission and addition experiments indicated that the activity could be reconstituted solely by domain V at a concentration 10 times higher than that of the intact 23S ribosomal RNA, whereas domain VI could enhance the activity in trans. These Þndings suggest that fragments of an RNA molecule have the ability to associate into a functional whole. The complete sequence of E. coli 23S ribo-somal RNA (rRNA) was first determined in 1980; in the following year, a model of its likely secondary structure was proposed (1). Subsequent extensive studies on rRNA se-quences of the ribosomal large subunit span