TY - JOUR
T1 - Assignment of imino proton signals of G-C base pairs and magnesium ion binding
T2 - An NMR study of bovine mitochondrial tRNA(Ser)(GCU) lacking the entire D arm
AU - Hayashi, Ikuko
AU - Yokogawa, Takashi
AU - Kawai, Gota
AU - Ueda, Takuya
AU - Nishikawa, Kazuya
AU - Watanabe, Kimitsuna
PY - 1997/6
Y1 - 1997/6
N2 - The mammalian mitochondrial tRNA(Ser)(GCU) (mt tRNA(Ser)(GCU)) has a unique structure in that it lacks the whole D arm. To elucidate its higher-order structure, we synthesized unmodified bovine mt tRNA(Ser)(GCU) using T7 RNA polymerase and measured its 1H-NMR spectrum in the imino proton region. Although the imino proton signals heavily overlapped, we succeeded in assigning all the seven imino proton signals of the G-C base pairs by a combination of base replacement and 15N-labeling of the G residues of a whole tRNA molecule or of the 3'-half fragment. The results indicate that the tRNA possesses the secondary structure that has been supposed on the basis of biochemical studies. Analysis of the effect of the magnesium concentration on the G-C pairs suggests that the acceptor and T stems do not form a co-axial helix, and that the core region of the tRNA does not interact with magnesium ions. These features are significantly different from those of canonical tRNAs. Despite this, it is very likely that the tRNA as a whole takes a nearly L-shape tertiary structure.
AB - The mammalian mitochondrial tRNA(Ser)(GCU) (mt tRNA(Ser)(GCU)) has a unique structure in that it lacks the whole D arm. To elucidate its higher-order structure, we synthesized unmodified bovine mt tRNA(Ser)(GCU) using T7 RNA polymerase and measured its 1H-NMR spectrum in the imino proton region. Although the imino proton signals heavily overlapped, we succeeded in assigning all the seven imino proton signals of the G-C base pairs by a combination of base replacement and 15N-labeling of the G residues of a whole tRNA molecule or of the 3'-half fragment. The results indicate that the tRNA possesses the secondary structure that has been supposed on the basis of biochemical studies. Analysis of the effect of the magnesium concentration on the G-C pairs suggests that the acceptor and T stems do not form a co-axial helix, and that the core region of the tRNA does not interact with magnesium ions. These features are significantly different from those of canonical tRNAs. Despite this, it is very likely that the tRNA as a whole takes a nearly L-shape tertiary structure.
KW - Assignment of imino proton signals
KW - H-NMR
KW - Magnesium effect
KW - Mitochondrial tRNA
KW - N-labeling
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U2 - 10.1093/oxfordjournals.jbchem.a021703
DO - 10.1093/oxfordjournals.jbchem.a021703
M3 - Article
C2 - 9354385
AN - SCOPUS:0030759652
VL - 121
SP - 1115
EP - 1122
JO - Journal of Biochemistry
JF - Journal of Biochemistry
SN - 0021-924X
IS - 6
ER -