Formation of SRP‐like particle induces a conformational change in E. coli 4.5S RNA

FEBS Letters

Lentzen, Georg¹  Dobberstein, Bernhard²  Wintermeyer, Wolfgang¹ 

[1] Institut für Molekularbiologie, Universität Witten/Herdecke, D-58448 Witten, Germany;Zentrum für Molekulare Biologie, Universität Heidelberg, D-69120 Heidelberg, Germany

关键词: 4.5S RNA;    Signal recognition particle;    P48 (FFh) protein;    Ribonucleoprotein;    Fluorescence labeling;    E. coli;    SRP;    signal recognition particle;    4.5S RNAF;    fluorescein labeled 4.5S RNA;   

DOI  :  10.1016/0014-5793(94)00599-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

E. coli P48 protein is homologous to the SRP54 component of the eukaryotic signal recognition particle. In vivo, P48 is associated with 4.5S RNA which shares a homology with eukaryotic SRP RNA. To study the interaction between P48 and 4.5S RNA in vitro, we used 4.5S RNA with fluorescein coupled to the 3′-terminal ribose. Upon binding of P48, the fluorescent 4.5S RNA shows a substantial decrease in fluorescence. Fluorescence quenching as well as anisotropy measurements reveal that the effect is not due to a direct interaction of P48 with the dye. This suggests that the binding of P48 induces a conformational change in 4.5S RNA which affects the structure at the 3′ end of the RNA. From equilibrium titrations with fluorescent 4.5S RNA, a dissociation constant of O.15 μm is obtained for the RNA · protein complex. The formation of the complex is not affected by GTP binding to or hydrolysis by P48.

【 授权许可】

Unknown