Conformational changes of aminoacyl‐tRNA and unchanged tRNA upon complex formation with polypeptide chain elongation factor Tu

FEBS Letters

Matsumoto, Rieko¹  Haruki, Mitsuru¹  Miyazawa, Tatsuo¹  Yokoyama, Shigeyuki¹  Hara-Yokoyama, Miki¹ 

[1] Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan

关键词: Elongation factor Tu;    Aminoacyl-tRNA;    Circular dichroism;    Conformation change;    (Thermus thermophilus HB8);    CD;    circular dichroism;    EF-Ts;    polypeptide chain elongation factor Ts;    EF-TU;    polypeptide chain elongation factor Tu;    Ile-tRNA;    isoleucyl-tRNAIle 1;    IleRS;    isoleucyl-tRNA synthetase;    s2T;    2-thioribothymidine;   

DOI  :  10.1016/0014-5793(90)81414-J

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The conformation change of Thermus thermophilus tRNA^Ile ₁ upon complex formation with T. thermophilus elongation factor Tu (EF-Tu) was studied by analysis of the circular dichroism (CD) bands at 315 nm (due to the 2-thioribothymidine residue in the T-loop) and at 295 nm (due to the core structure of tRNA). Formation of the ternary complex of isoleucyl-tRNA^Ile ₁ and EF-Tu·GTP increased the intensities of these CD bands, indicating stabilization of the association between the T-loop and the D-loop and also a significant conformation change of the core region. Upon complex formation of EF-Tu·GTP and unchanged tRNA, however, the conformation of the core region is not changed, while the association of the two loops is still stabilized. On the other hand, the binding with EF-Tu·GDP does not appreciably affect the conformation of isoleucyl-tRNA or unchanged tRNA. These indicate the importance of the γ-phosphate group of GTP and the aminoacyl group in the formation of the active complex of aminoacyl-tRNA and EF-Tu·GTP.

【 授权许可】

Unknown