Amal Seffouh, Chirstian Trahan, Tanzila Wasi, Nikhil Jain, Kaustuv Basu, Robert A Britton, Marlene Oeffinger, Joaquin Ortega
Nucleic Acids Research, gkac059, doi:10.1093/nar/gkac059
Ribosomal subunits in bacteria assemble according to energy landscapes comprised of multiple parallel pathways. In this study, the authors identified a critical maturation step in the late assembly stages of the large 50S ribosomal subunit in bacteria. This step represents a merging point where all parallel assembly pathways of the ribosomal particles converge. At this critical step, the convergent assembly intermediate that accumulates in cells exists in a ‘locked’ state, and its maturation is paused. The RbgA protein acts on this critical step to ‘unlock’ the last maturation steps involving folding of the functional sites. Through this mechanism, RbgA ensures that the functional sites of the 50S mature last.