Pathways to Specialized Ribosomes: The Brussels Lecture.

"Specialized ribosomes" is a topic of intense debate and research whose provenance can be traced to the earliest days of molecular biology. Here, the history of this idea is reviewed, and critical literature in which the specialized ribosomes have come to be presently defined is discussed. An argument supporting the evolution of a variety of ribosomes with specialized functions as a consequence of selective pressures acting on a near-infinite set of possible ribosomes is presented, leading to a discussion of how this may also serve as a biological buffering mechanism. The possible relationship between specialized ribosomes and human health is explored. A set of criteria and possible approaches are also presented to help guide the definitive identification of "specialized" ribosomes, and this is followed by a discussion of how synthetic biology approaches might be used to create new types of special ribosomes.