Modulation of ribosomal recruitment to 5′‐terminal start codons by translation initiation factors IF2 and IF3

FEBS Letters

Moll, Isabella¹  Bläsi, Udo¹  Gualerzi, Claudio O.²  Grill, Sonja¹  Hasenöhrl, David¹ 

[1] Institute of Microbiology and Genetics, Vienna Biocenter, University of Vienna, Dr. Bohrgasse 9, 1030 Vienna, Austria;Laboratory of Genetics, Department of Biology, University of Camerino, 62032 Camerino, Italy

关键词: Initiation factor;    Leaderless mRNA;    Translation;    IF;    translation initiation factor;    rbs;    ribosome binding site;    SD sequence;    Shine–Dalgarno sequence;   

DOI  :  10.1016/S0014-5793(01)02378-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Sequence determinants and structural features of the RNA govern mRNA–ribosome interaction in bacteria. However, ribosomal recruitment to leaderless mRNAs, which start directly with the AUG start codon and do not bear a Shine–Dalgarno sequence like canonical mRNAs, does not appear to rely on 16S rRNA–mRNA interactions. Here, we have studied the effects of translation initiation factors IF2 and IF3 on 30S initiation at a 5′-terminal AUG and at a competing downstream canonical ribosome binding site. We show that IF2 affects the forward kinetics of 30S initiation complex formation at the 5′-terminal AUG as well as the stability of these complexes. Moreover, the IF2:IF3 molar ratio was found to play a decisive role in translation initiation of a leaderless mRNA both in vitro and in vivo indicating that the translational efficiency of an mRNA is not only intrinsically determined but can be altered depending on the availability of components of the translational machinery.

【 授权许可】

Unknown