Frameshifting in the expression of the Escherichia coli trpR gene is modulated by translation initiation.
The Escherichia coli trpR gene encodes the 108-amino-acid-long Trp repressor. We have shown previously that a +1 frameshifting event occurs during the expression of trpR, resulting in the synthesis of an additional (+1 frame) polypeptide. Using trpR-lac'Z fusions, we have recently found that the transition from the 0 to the +1 frame occurs via the bypassing of a 55-nucleotide-long segment of the trpR+1-lac'Z mRNA (I. Benhar, and H. Engelberg-Kulka, Cell 72:121-130, 1993). Here we show that the frequency of trpR frameshifting (or bypassing) can be regulated both in vivo and in vitro. This frequency is inversely proportional to the rate of initiation of translation of the trpR gene. Hence, modulating the level of translation initiation affects the frequency of frameshifting.
Department of Molecular Biology, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
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Benhar
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Miller
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Engelberg-Kulka
D001426:Bacterial Proteins; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics*; D010442:Peptide Chain Initiation, Translational / Q000235:genetics*; D014176:Protein Biosynthesis / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics*; D029968:Escherichia coli Proteins
D001426:Bacterial Proteins; D012097:Repressor Proteins; C027190:TRPR protein, E coli; D029968:Escherichia coli Proteins