Ribosomal protein S1 of Escherichia coli is the effector for the regulation of its own synthesis.

J Skouv,J Schnier,M D Rasmussen,A R Subramanian,S Pedersen

doi:10.1016/s0021-9258(17)44866-6

J Skouv, J Schnier + Show 3 more

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https://doi.org/10.1016/s0021-9258(17)44866-6

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Abstract

To facilitate the study of the regulation of the rpsA gene, a translational fusion between the rpsA gene and the lacZ gene was constructed. Synthesis of the fusion protein was repressed about 10-fold when rpsA was supplied in trans on a multicopy plasmid. This repression is similar to the post-transcriptional regulation previously found for the wild type rpsA gene. Addition of purified protein S1 to a coupled in vitro transcription-translation system caused a specific reduction in the synthesis of the rpsA-lacZ fusion protein. Addition of various subdomain fragments of protein S1 to the coupled in vitro system showed that the N-terminal fragment, possessing the ribosome binding domain of protein S1, was able to repress the synthesis of the rpsA-lacZ fusion protein. In contrast, fragments from the C-terminal region, containing the nucleic acid binding domain of protein S1, were inactive in this repression. Induction of truncated rpsA genes, coding for either the N-terminal 101 or 329 amino acids caused a reduction in the synthesis of the chromosomally encoded protein S1, thus confirming in vivo that the N-terminal part of protein S1 represses rpsA expression.

Highlights

Ribosomal Protein Sl of Escherichia coli Is the Effector for the Regulation of Its Own Synthesis*
Repression by the Intact rpsA Gene in Viuo-In Table I we show that intact rpsA supplied in trans is able to repress the synthesis of the rpsA-1acZ fusion protein in vivo
To facilitate the study of the rpsA regulation, a translational fusion was constructed betwen rpsA and the reporter gene 1acZ

Summary

Introduction

Ribosomal Protein Sl of Escherichia coli Is the Effector for the Regulation of Its Own Synthesis*. To facilitate the study of the regulation of the rpsA gene, a translational fusion between the rpsA gene and the 1acZ gene was constructed. Synthesis of the fusion protein was repressed about lo-fold when rpsA was supplied in trans on a multicopy plasmid. This repression is similar to the post-transcriptional regulation previously found for the wild type rpsA gene. Addition of purified protein Sl to a coupled in vitro transcription-translation system caused a specific reduction in the synthesis of the rpsA-1acZ fusion protein. Terminal fragment, possessing the ribosome binding domain of protein S 1, was able to repress the synthesis of the rpsA-1acZ fusion protein. Fragments from the C-terminal region, containing the nucleic acid binding domain of protein Sl, were inactive in this repression

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