A lethal mutation which affects the maturation of ribosomes

Ribosome biogenesis and the translation process in Escherichia coli

Translation, the decoding of mRNA into protein, is the third and final element of the central dogma. The ribosome, a nucleoprotein particle, is responsible and essential for this process. The bacterial ribosome consists of three rRNA molecules and approximately 55 proteins, components that are put together in an intricate and tightly regulated way. When finally matured, the quality of the particle, as well as the amount of active ribosomes, must be checked. The focus of this review is ribosome biogenesis in Escherichia coli and its cross-talk with the ongoing protein synthesis. We discuss how the ribosomal components are produced and how their synthesis is regulated according to growth rate and the nutritional contents of the medium. We also present the many accessory factors important for the correct assembly process, the list of which has grown substantially during the last few years, even though the precise mechanisms and roles of most of the proteins are not understood.

A new ribosomal mutation which affects the two ribosomal subunits in Escherichia coli

A new ribosomal mutant resistant to erythromycin is described. The product of the gene eryC seems to be implicated in the assembly of the two ribosomal subunits, particularly in the maturation process of the RNA 23S and 16S.