Eukaryotic selenocysteine tRNA has the 9/4 secondary structure

FEBS Letters

Goto, Chiharu¹  Mizutani, Takaharu¹ 

[1] Faculty of Pharmaceutical Sciences, Nagoya City University, Mizuho-ku, Nagoya 467-8603, Japan

关键词: tRNA;    Selenocysteine;    Selenium;    tRNA structure;    Sec;    selenocysteine;    SecS;    selenocysteine synthase;    SerRS;    Seryl-tRNA synthetase;    AA;    aminoacyl-acceptor;    T;    TψC;    D;    dihydrouridine;    AC;    anticodon;    V;    variable arm;   

DOI  :  10.1016/S0014-5793(00)01104-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

There are two secondary structure models for the eukaryotic selenocysteine (Sec) tRNA^Sec. One model, the 9/4 structure, was experimentally tested and possesses acceptor and T-stems with 9 and 4 bp, respectively [Sturchler et al., 1993; Hubert et al., 1998]. The other one, the 7/5 secondary structure with a bulge in the T-stem, was derived from theoretical calculation [Ioudovitch and Steinberg, 1999]. In this report, we show more experimental results supporting the 9/4 secondary structure. Several tRNA^Sec mutants, whose secondary structure can adopt only the 9/4 structure, were active for serylation and selenylation. Some mutants that cannot base-pair between positions 26 and 44 to provide the 6 bp anticodon stem were still active, inconsistent with the model by Steinberg. We also show that the orientation of the V-arm directly or indirectly influences the selenylation activity, and that the rigid 6 bp D-stem is important. Finally, we conclude that all tRNAs^Sec possess the 13 bp domain II made by the stacking of the colinear AA and T-stems, whether they present the 9/4 structure in Eukarya and Archaea or the 8/5 structure in bacteria.

【 授权许可】

Unknown