Formation of circular polyribosomes in wheat germ cell‐free protein synthesis system

FEBS Letters

Miura, Kin-Ichiro¹  Endo, Yaeta²  Takai, Kazuyuki²  Takei, Toshiaki¹  Yazaki, Kazumori³  Ogasawara, Tomio²  Sawasaki, Tatsuya²  Kamura, Nami²  Madin, Kairat² 

[1] Proteios Research, Inc., Tebiro, Kamakura 248-8555, Japan;Cell-free Science and Technology Research Center, and The Venture Business Laboratory, Ehime University, Matsuyama 790-8577, Japan;Department of Ultrastructural Research, Tokyo Metropolitan Institute of Medical Science, Honkomagome, Bunkyo-ku, Tokyo 113, Japan

关键词: Wheat germ;    Cell-free translation;    Electron microscopic observation;    Circular polysome;    No-cap non-poly(A) tail;   

DOI  :  10.1016/S0014-5793(04)00221-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We report a morphological study of functioning ribosomes in a efficient and robust cell-free protein synthesis system prepared from wheat embryos. Sucrose density gradient analysis of translated mixtures programmed with luciferase mRNAs having different 5′ and 3′ untranslated regions showed formation of large polysomes. Electron microscopic examination of translation mixtures programmed with those of capped and polyadenylated mRNA revealed that ribosomes assemble into a circular-type polysome in vitro. Furthermore, a series of experiments using mRNAs lacking either cap, poly(A) tail or both also resulted in the formation of circular polysomes, which are indistinguishable from those with the original mRNA. The wheat germ cell-free system may provide a good experimental system for understanding functional ribosomes at the molecular level.

【 授权许可】

Unknown