Where Do We Come From? What Are We? Where Are We Going?
For millennia, humans have pondered these existential questions, which were beautifully posed by Gaugin in his 1898 masterpiece. Only by retracing the complex path that brought us here, can we begin to comprehend our place in the vast universe and in our immediate physical and biological world. Today, science is developing the tools required to define that path. We stand at the edge of a precipice—and can now understand the natural processes that planted the seeds of life on the primordial Earth. The search for the molecular origin of life has been largely focused on uncovering the processes that led to RNA —a molecule capable of both information storage and chemical catalysis. We have a different focus—the ribosome. Carl Woese and George Fox selected the ribosome to address some of the deepest questions in biology over fifty years ago, and in doing so, they discovered life's fundamental lineages. Indeed, the ribosome is a window to primeval events, molecular structures, and (geo-) chemical processes that directed the broad course of evolution of life on Earth. Our Center for the Discovery of the Origin of Life on Earth is supported by NASA Astrobiology program, and focuses on dissecting and literally resurrecting the ancient ribosome. We will rewind the “tape of life” by mapping, at the molecular level, the processes by which RNA and protein joined forces to create the ribosome—the only surviving functional component dating from life’s origin. Through our scientific work, we will reveal how the original and most profound symbiotic relationship in all of biology, that of polypeptide and polynucleotide, took place and evolved to become life as we know it. Today, we recognize the ribosome (and the translation system in general) as unique in the biological world. The ribosome’s core is conserved among all domains of life on Earth. It translates information from polynucleotide to polypeptide in a spectacular molecular choreography that follows a unique and universal genetic code. The mechanics of translation were recently exposed in detail by the solution of the ribosome’s structure. The translation system retains an interpretable molecular record of the history of life which serves as our molecular “time machine.” We will retrace the step-by-step evolution of the ribosome from its existing form to its most ancient ancestor and thereby discover the origin of life itself.