The ribosome can be thought of as a decryption device housed within the cell. It is able to decipher the genetic code, which is delivered in the form of messenger ribonucleic acid (mRNA), and translate it into a specific sequence of amino acids. The final assembly of amino acids into long protein chains also takes place in these enzyme complexes. Without ribosomes, a cell would be unable to produce any proteins. Due to their central function, these enzyme complexes have long been the focus of attention of biologists.
In order to obtain a better understanding of ribosomes, which are found in all cells, it is imperative to know their exact composition and structure. Over the past 15 years, Nenad Ban, professor at ETH Zurich, has made a significant contribution to not only the elucidation of the ribosome structure of bacteria, but also of higher organisms, termed eukaryotes, which include fungi, plants and animals.
Structure determination with obstacles
Until now, the molecular structure of the ribosomes found in mitochondria, the power plants of the cell, was still largely unknown. Mitochondrial ribosomes differ considerably from the 'ordinary' ribosomes found in the cytoplasm, which are composed of 60% ribonucleic acids (RNA) and 40% protein components. In the case of mitochondrial ribosomes, RNA accounts for just under a third of the entire complex. One reason for this is that the RNA molecules have shortened significantly over the course of evolutionary history. Mitochondrial ribosomes in the cell are primarily localised at the inner membrane of mitochondria and are present within the cell in a far smaller number than the cytoplasmic ribosomes. This makes them more difficult to isolate, hampering progress of research in the field.
A team of researchers from the ETH research groups of Nenad Ban and Ruedi Aebersold have now succeeded in elucidating the structure of the large subunit of the mitochondrial ribosomes from mammal
|Contact: Nenad Ban|