The Earliest Discovery of the Role of Magnesium Ions on Stabilizing the Tertiary Structure of the Transfer RNA and Its Biological Significance <br>—A Short Memoir

Abstract

In early of 1960s, I was a graduate student studying on tRNA biochemistry. In the course of the research, the magnesium ions stabilized the tertiary structure of tRNA, resulting in its resistance to enzymatic degradation was discovered independently. The experiment of deaminated (denatured) tRNA obtained from native tRNA was designed and conducted and further proved the validity of this finding. It was found that magnesium ions could stabilize the tertiary structure of the natrive tRNA but could not stabilize structure of the deaminated tRNA. In term of the methodology, this stabilization technique has been widely applied in sequencing analysis of RNA and has greatly promoted the progress in the study of primary structure of RNA. More importantly, the stabilization of the tertiary structure of RNA by magnesium ions plays a key role both in the processing of messenger RNAs and the ribozyme activity. After our first article in Chinese was published in 1963, a paper of Nishimura & Novelli came into our note. The received date of their paper was March 22 of 1963, only 4 days earlier than that of our first paper. Thus, we and Nishimura & Novelli made almost at the same time the earliest discovery of the role of magnesium ions on stabilizing the tertiary structure of the transfer RNA and thus resulted in resistance of tRNA degradation by enzymes. However, this discovery was not initially appreciated for a period of time but was finally “visualized” and proved by X-ray crystal structure of yeast phenylalanine tRNA, which has provided more accurate information on the geometry of the magnesium-binding sites in tRNA.