Maturation of the ribosome is a complex operation. Work by an LMU team now shows that the 90S precursor of the small 40S subunit undergoes a “molting” process, during which it progressively discards its outermost components.
Protein synthesis, programmed by the genetic information encoded in the DNA, is perhaps the most crucial process that takes place in biological cells. Proteins are indispensable for all organisms, because they are responsible for performing a vast range of biological functions. Indeed, the molecular machines that put proteins together—which are known as ribosomes—are themselves partly made up of specific proteins. The second vital ingredient of every ribosome is a small set of specific RNAs, which serve as scaffolds to which ribosomal proteins can be specifically attached. The synthesis of ribosomes is therefore an extremely complex, multistep process, which includes both assembly and maturation stages. This complexity