Open AccessAssignment of the magnetic resonances of the imino protons and methyl protons of Bombyx mori tRNA GCC Gly and the effect of ion binding on its structure
Author(s) -
AMANO Mayumi,
KAWAKAMI Makoto
Publication year - 1992
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1992.tb17468.x
Subject(s) - transfer rna , crystallography , bombyx mori , protein tertiary structure , base pair , stereochemistry , spermine , chemistry , hydrogen bond , acceptor , molecule , rna , enzyme , physics , biochemistry , organic chemistry , dna , gene , condensed matter physics
The magnetic resonances in the low‐field H‐NMR spectra of Bombyx mori tRNA GCC Gly , corresponding to the hydrogen‐bonded imino protons of the helical stems and tertiary base pairs, could be tentatively assigned by means of the sequential nuclear Overhauser effects. While B. mori tRNA GCC Gly does not contain the G19C56 tertiary base pair, the D20G57 base pair exists between the D and T loops, which was not found in the X‐ray crystal structure of yeast tRNA Phe . The effects of Mg 2+ , spermine and temperature on the conformation of this tRNA have also been examined based on the behavior of the assigned resonance signals. Mg 2+ stabilize the D and T stems and the tertiary structure between the D and T loops. Spermine affects the resonances of the D and anticodon stems, and A23G9, but does not stabilize them. While the acceptor stem melts sequentially from both ends (G7C66 and G1C72) with increasing temperature, the anticodon stem melts from only one end (G39C31) and the G26C44 base pair is the most stable. In the tertiary structure between the variable loop and D stem, G10G45 melts first and G22G46 last. Yeast tRNA Phe has also been examined, and the results were compared with those for B. mori tRNA Gly .