Yamada Yuko, Matsugi Jitsuhiro, Ishikura Hisayuki
Department of Biochemistry, Jichi Medical School, 3311-1 Yakushiji, Minamikawachi-machi, Tochigi-ken 329-0498, Japan.
Biochim Biophys Acta. 2003 Apr 15;1626(1-3):75-82. doi: 10.1016/s0167-4781(03)00045-9.
The tRNA1Ser (anticodon VGA, V=uridin-5-oxyacetic acid) is essential for translation of the UCA codon in Escherichia coli. Here, we studied the translational abilities of serine tRNA derivatives, which have different bases from wild type at the first positions of their anticodons, using synthetic mRNAs containing the UCN (N=A, G, C, or U) codon. The tRNA1Ser(G34) having the anticodon GGA was able to read not only UCC and UCU codons but also UCA and UCG codons. This means that the formation of G-A or G-G pair allowed at the wobble position and these base pairs are noncanonical. The translational efficiency of the tRNA1Ser(G34) for UCA or UCG codon depends on the 2'-O-methylation of the C32 (Cm). The 2'-O-methylation of C32 may give rise to the space necessary for G-A or G-G base pair formation between the first position of anticodon and the third position of codon.
tRNA1Ser（反密码子VGA，V = 尿苷 - 5 - 氧乙酸）对于大肠杆菌中UCA密码子的翻译至关重要。在此，我们使用含有UCN（N = A、G、C或U）密码子的合成mRNA，研究了反密码子第一位与野生型不同的丝氨酸tRNA衍生物的翻译能力。具有反密码子GGA的tRNA1Ser(G34)不仅能够识别UCC和UCU密码子，还能识别UCA和UCG密码子。这意味着在摆动位置允许形成G - A或G - G碱基对，并且这些碱基对是非规范的。tRNA1Ser(G34)对UCA或UCG密码子的翻译效率取决于C32（Cm）的2'-O-甲基化。C32的2'-O-甲基化可能会为反密码子第一位与密码子第三位之间形成G - A或G - G碱基对提供所需的空间。
