Prebiotic Peptide Bond Formation by the Protoribosome: A Probable Link between the RNA and the Protein Dominated Worlds
A.Yonath
Weizmann Institute of Science 76100, Rehovot, Israel.
High-resolution structures of ribosomes from various organisms or tissues, determined by us and elsewhere, show that the peptidyl transferase center (PTC) is a semi-symmetrical RNA- made pocket, located in the core of the otherwise asymmetric ribosome. The three-dimensional structure and the nucleotide sequence of this region are highly conserved among all domains of life, hinting at its prebiotic origin, and implying that it could be a remnant of a prebiotic entity, which underwent limited evolution.
These characteristics, in addition to the findings that RNA can create itself and may possess catalytic activities, led to our “protoribosome” concept, which was recently proven experimentally via the successful peptide bond formation (monitored by MALDI and MS) by our representative lab constructs. Hence, it is conceivable that this entity was the origin of the ribosome, therefore the origin of life, which existed in the RNA dominated world. As such it is suggested to be the missing link from the RNA dominating world to the contemporary protein/nucleic acids life. After achieving this feat, we are now attempting determination of the structure of “protoribosomes” to further verify our hypothesis of pocket formation and its role in peptide bond formation.
The following scientists participated in this study: I. Agmon, T. Bose, Disha Gajanan Hiregange, A. André Rivalta, K. Shanmugha Rajan, C. Davidovich, M. Krupkin, G. Fridkin, N. Dinger, Y. Peleg, A. Bashan