Loss of a single methylation in 23S rRNA delays 50S assembly at multiple late stages and impairs translation initiation and elongation

Abstract

Significance Ribosome biogenesis is a complicated but efficient process requiring numerous steps of protein binding and RNA conformational rearranging. The methylation of specific nucleotides in functional regions by methyltransferases is crucial for both assembly and function of ribosomes. We characterized the structures and function of immature 50S particles from an rrmJ gene (methyltransferase for U2552 of the 23S rRNA) deletion Escherichia coli strain. With the absence of the 2′-O-methylation of U2552, the assembly of the 50S subunit is delayed at multiple late stages. Loss of this methylation also results in compromised translation activities, particularly in the initiation and the elongation steps. These results illustrate an example of chemical modification of rRNA playing a role in both ribosome biogenesis and protein translation.