Reconstitution of functional 50S ribosomes from in vitro transcripts of Bacillus stearothermophilus 23S rRNA.

In vitro transcripts of Bacillus stearothermophilus 23S rRNA can be reconstituted into catalytically active 50S ribosomal subunits with an efficiency only 3-4-fold lower than that of natural 23S rRNA. Thus, post-transcriptional modifications in 23S rRNA are not essential for the assembly or function of the 50S subunit of the ribosome. This reconstitution sytem has been used to characterize the peptidyl transferase activity of site-directed mutations in 23S rRNA at positions G2252, U2506, U2584, and A2602 (Escherichia coli numbering), demonstrating its potential for the analysis of the role played by 23S rRNA in the function of the 50S subunit of the ribosome.