Mutation that affects pepN translation initiation in Escherichia coli.

S Gharbi, M Bally, A Lazdunski, M Murgier

Index: Biochimie 68(10-11) , 1159-63, (1986)

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Abstract

Mutants altered in their expression of the hybrid pepN-lacZ gene have been selected for resistance to p-nitrophenyl-beta-D-thiogalactopyranoside (a bacteriostatic compound that enters the cells via lac permease). A unique mutation decreasing the level of pepN expression to 9% of that of the wild type has been studied in detail. This mutation controls in cis the expression of the pepN gene. The pepN region from a pepN-lacZ gene fusion has been cloned and sequenced. Comparison of the mutant and wild type sequences indicates that the mutation lies between the Shine-Dalgarno sequence (AGGT) and the initiation codon (AUG). This mutation is a T----C transition which might allow the formation of a stable secondary structure in the region of translation initiation thus decreasing the level of pepN expression.