Thermostable valyl‐tRNA, isoleucyl‐tRNA and methionyl‐tRNA synthetases from an extreme thermophile Thermus thermophilus HB8: protein structure and Zn2+ binding

FEBS Letters

Kohda, Daisuke¹  Miyazawa, Tatsuo¹  Yokoyama, Shigeyuki¹ 

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

关键词: Valyl-tRNA synthetase;    Isoleucyl-tRNA synthetase;    Methionyl-tRNA synthetase;    Thermus thermophilus;    Amino acid composition;    Zinc content;   

DOI  :  10.1016/0014-5793(84)81069-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Thermostable valyl-tRNA, isoleucyl-tRNA and methionyl-tRNA synthetases have been purified from an extreme thermophile, Thermus thermophilus HB8. Valyl-tRNA and isoleucyl-tRNA synthetases are found to be monomer proteins (M _r 108000 and 129000, respectively), while methionyl-tRNA synthetase is a dimer protein (M _r 150000). These enzymes are very similar with respect to amino acid compositions and α-helix contents as estimated by circular dichroism analyses. Furthermore, two Zn²⁺ are tightly bound to each of these synthetases. These data suggest that valyl-tRNA and isoleucyl-tRNA synthetases consist of two domains, each corresponding to the subunit of methionyl-tRNA synthetase.

【 授权许可】

Unknown