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Cis control of gene expression in E.coli by ribosome queuing at an inefficient translational stop signal
Author(s) -
Jin Haining,
Björnsson Asgeir,
Isaksson Leif A.
Publication year - 2002
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdf424
Subject(s) - biology , ribosome , gene expression , genetics , gene , translational regulation , translation (biology) , messenger rna , microbiology and biotechnology , rna
An UGA stop codon context which is inefficient because of the 3′‐flanking context and the last two amino acids in the gene protein product has a negative effect on gene expression, as shown using a model protein A′ gene. This is particularly true at low mRNA levels, corresponding to a high intracellular ribosome/mRNA ratio. The negative effect is smaller if this ratio is decreased, or if the distance between the initiation and termination signals is increased. The results suggest that an inefficient termination codon can cause ribosomal pausing and queuing along the upstream mRNA region, thus blocking translation initiation of short genes. This cis control effect is dependent on the stop codon context, including the C‐terminal amino acids in the gene product, the translation initiation signal strength, the ribosome/mRNA ratio and the size of the mRNA coding region. A large proportion of poorly expressed natural Escherichia coli genes are small, and the weak termination codon UGA is under‐represented in small, highly expressed E.coli genes as compared with the efficient stop codon UAA.