Research Structurally heterogeneous ribosomes cooperate in protein synthesis in bacterial cells

Even though the process of protein synthesis is highly conserved in all kingdoms of life, the structure and composition of the cellular machinery for protein synthesis, the ribosome, can differ between organisms, tissues and even within a single cell. Whether such heterogeneity reflects genuine functional specialization of ribosomes is a highly debated question. In a collaboration between the groups of Stefan Pfeffer (ZMBH), Sergey Melnikov (Newcastle University) and Christopher Hill (University of York), the shared first-authors Karla Helena-Bueno and Sophie Kopetschke used cryo-electron microscopy to investigate the function of individual structurally heterogeneous ribosomes within bacterial cells. Their work revealed that ribosomes differing in the copy number of ribosomal protein bS20 were indistinguishable in their core activities and cooperated in simultaneous translation of mRNAs, demonstrating a case of functionally neutral ribosome heterogeneity.