期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1974
卷号：71
期号：10
页码：4237-4240
DOI：10.1073/pnas.71.10.4237
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The binding of paramagnetic rare earth ions to yeast tRNAPhe shifts some resonances in the low-field nuclear magnetic resonance spectrum that have been assigned to ring nitrogen protons of specific Watson-Crick base pairs. The changes in the nuclear magnetic resonance spectrum as the tRNA is titrated with Eu3+ indicate that 4 (or 5) Eu3+ ions are tightly bound, that the metal binding is in the fast exchange limit, and that the binding to different sites in the molecule is sequential rather than cooperative. The first metal bound simultaneously shifts resonances associated with the dihydrouridine and the -C-C-A stem. This permits us to conclude that the folding of the tRNAPhe in solution brings the phosphate backbone of the -C-C-A and the dihydrouridine stems into close proximity. A model of the three-dimensional structure of tRNAPhe incorporating this new information appears to be compatible with the results obtained from x-ray diffraction.
