Construction of the ‘minimal’ SRP that interacts with the translating ribosome but not with specific membrane receptors in Escherichia coli

FEBS Letters

Avdeeva, Olga N²  Myasnikov, Alexander G²  Brimacombe, Richard¹  Bogdanov, Alexey A²  Dontsova, Olga A²  Sergiev, Petr V² 

[1] Max-Planck Institut fur Molekulare Genetik AG-Ribosomen, Ihnestrasse 73, 14195 Berlin, Germany;Department of Chemistry, Moscow State University, Moscow 119899, Russia

关键词: Signal recognition particle;    Ribosome;    Translation arrest;    Ffh;    4.5S RNA;   

DOI  :  10.1016/S0014-5793(02)02332-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Escherichia coli signal recognition particle (SRP) consists of 4.5S RNA and Ffh protein. In contrast to eukaryotes, it remains unclear whether translation arrest takes place in prokaryotic cells. To study this problem we constructed a fusion of the M domain of Ffh protein with a cleavable affinity tag. This mutant Ffh, in a complex with 4.5S RNA, can bind signal peptide at the translating ribosome but is unable to bind the membrane. This SRP–ribosome complex should accumulate in the cell if translation is arrested. To test this, the complex was purified from the cells by ultracentrifugation and affinity chromatography. The composition of the complex was analyzed and found to consist of ribosomal RNAs and proteins, the Ffh M domain and 4.5S RNA. The accumulation of this complex in the cell in significant amounts indicated that SRP-mediated translation arrest did occur in bacterial cells.

【 授权许可】

Unknown