TY - JOUR
T1 - A novel wobble rule found in starfish mitochondria. Presence of 7- methylguanosine at the anticodon wobble position expands decoding capability of tRNA
AU - Matsuyama, Satoshi
AU - Ueda, Takuya
AU - Crain, Pamela F.
AU - McCloskey, James A.
AU - Watanabe, Kimitsuna
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1998/2/6
Y1 - 1998/2/6
N2 - In the starfish mitochondrial (mt) genome, codons AGA and AGG (in addition to AGU and AGC) have been considered to be translated as serine. There is, however, only a single candidate mt tRNA gene responsible for translating these codons and it has a GCT anticodon sequence, but guanosine at the first position of the anticodon should base pair only with pyrimidines according to the conventional wobble rule. To solve this enigma, the mt tRNA (GCU/ser) was purified, and sequence determination in combination with electrospray liquid chromatography/mass spectrometry revealed that 7- methylguanosine is located at the first position of the anticodon. This is the first case in which a tRNA has been found to have 7-methylguanosine at the wobble position. It is suggested that methylation at N-7 of wobbling guanosine endows the tRNA with the capability of forming base pairs with all four nucleotides, A, U, G, and C, and expands the repertoire of codon- anticodon interaction. This finding indicates that a nonuniversal genetic code in starfish has been generated by base modification in the tRNA anticodon.
AB - In the starfish mitochondrial (mt) genome, codons AGA and AGG (in addition to AGU and AGC) have been considered to be translated as serine. There is, however, only a single candidate mt tRNA gene responsible for translating these codons and it has a GCT anticodon sequence, but guanosine at the first position of the anticodon should base pair only with pyrimidines according to the conventional wobble rule. To solve this enigma, the mt tRNA (GCU/ser) was purified, and sequence determination in combination with electrospray liquid chromatography/mass spectrometry revealed that 7- methylguanosine is located at the first position of the anticodon. This is the first case in which a tRNA has been found to have 7-methylguanosine at the wobble position. It is suggested that methylation at N-7 of wobbling guanosine endows the tRNA with the capability of forming base pairs with all four nucleotides, A, U, G, and C, and expands the repertoire of codon- anticodon interaction. This finding indicates that a nonuniversal genetic code in starfish has been generated by base modification in the tRNA anticodon.
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U2 - 10.1074/jbc.273.6.3363
DO - 10.1074/jbc.273.6.3363
M3 - Article
C2 - 9452455
AN - SCOPUS:0032488826
VL - 273
SP - 3363
EP - 3368
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 6
ER -