Abstract
In order to select mutants that would help to characterize the post-transcriptional regulation of rpsA, we constructed a strain in which the growth rate on lactose minimal medium is determined by the amount of an rpsA-lacZ′ α-fragment fusion protein produced, even when this is encoded by a high-copy-number plasmid. In the parental strain, synthesis of the fusion protein is repressed by a wild-type rpsA gene, present on a compatible plasmid. Twenty-eight spontaneous and independent mutants, all of them mapping in the rpsA leader region, were isolated as strains that showed higher growth rates, on lactose medium, due to increased synthesis of the rpsA lacZ′ fusion protein. Among these mutants only three sequence changes were found, mapping 9, 10 and 27 bases upstream of the rpsA start codon. At both the −9 and −10 positions an A to G transition and at −27 a C to G transversion all resulted in a sequence with better complementarity to the 3′ end of 16S rRNA. We also isolated two mutations mapping in the plasmid-encoded rpsA structural gene: an ochre nonsense mutation in codon 15 of the rpsA gene and a frameshift mutation, deleting the T residue at position + 1186. To facilitate the in vitro assay of α-fragment activity we also constructed a strain that overproduces the α-acceptor fragment four-fold relative to a strain that is diploid for this lacZΔM15 allele.
Similar content being viewed by others
References
Bear DG, Ng R, van Derver D, Johnson NP, Thomas G, Schleich T, Noller HF (1976) Alteration of polynucleotide secondary structure by ribosomal protein S1. Proc Natl Acad Sci USA 73:1824–1828
Beckwith JR (1964) A deletion analysis of the lac operator region in Escherichia coli. J Mol Biol 8:427–430
Casadaban M, Cohen SN (1980) Analysis of gene control signals by DNA fusion and cloning in Escherichia coli. J Mol Biol 138:179–207
Cerretti DP, Mattheakis LC, Kearney KR, Vu L, Nomura M (1988) Translational regulation of the spc operon of E. coli: identification and structural analysis of the target site for S8 repressor protein. J Mol Biol 204:309–329
Christiansen L, Pedersen S (1981) Cloning, restriction endonuclease mapping and post-transcriptional regulation of rpsA, the structural gene for ribosomal protein S1. Mol Gen Genet 181:548–551
Clark B, Maaløe O (1967) DNA and the division cycle in Escherichia coli. J Mol Biol 23:99–112
Dahlberg AE, Dahlberg JE (1975) Binding of ribosomal protein S1 of Escherichia coli to the 3′ end of 16S rRNA. Proc Natl Acad Sci USA 72:2940–2944
Draper DE, von Hippel PH (1978) Nucleic acid binding properties of Escherichia coli ribosomal protein S1. J Mol Biol 122:321–338
Golinska B, Millon R, Backendorf C, Olomucki M, Ebel JP, Ehresmann B (1981) Identification of a 16S RNA fragment cross-linked to protein S1 within Escherichia coli ribosomal 308 subunits by the use of a crosslinking agent: Ethyl 4-azidobenzoyl-amino-acetimidate. Eur J Biochem 115:479–484
Gregory RJ, Cahill PBF, Thurlow DL, Zimmermann RA (1988) Interaction of Escherichia coli ribosomal protein S8 with its binding sites in ribosomal RNA and messenger RNA. J Mol Biol 204:295–307
Kohara Y, Akiyama K, Isono K (1987) The physical map of the whole E. coli chromosome: Application of a new strategy for rapid analysis and sorting of a large genomic library. Cell 50:495–508
Lin S, Zabin D (1972) β-galactosidase: Rates of synthesis and degradation of incomplete chains. J Biol Chem 247:2205–2211
Maxam AM, Gilbert W (1980) Sequencing end-labelled DNA with base-specific chemical cleavages. Methods Enzymol 65:499–566
Miller J (1972) Experiments in molecular genetics. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York
Morrison SL, Zipser D (1970) Termination fragments from nonsense mutations in the Z gene of the lac operon of Escherichia coli. J Mol Biol 50:359–371
Pedersen S, Skouv J, Kajitani M, Ishihama A (1984) Transcriptional organization of the rpsA operon of Escherichia coli. Mol Gen Genet 196:135–140
Petersen C (1987) The functional stability of the lacZ transcript is sensitive towards sequence alterations immediately downstream of the ribosome binding site. Mol Gen Genet 209:179–187
Philippe C, Portier C, Mougel M, Grunberg-Manago M, Ebel JP, Ehresmann B, Ehresmann C (1990) Target site of Escherichia coli ribosomal protein S15 on its mRNA. Conformation and interaction with the protein. J Mol Biol 211:415–426
Portier C, Dondon L, Grunberg-Manago M (1990) Translational autocontrol of the Escherichia coli ribosomal protein S15. J Mol Biol 211:407–414
Reeh S, Pedersen S, Friesen JD (1976) Biosynthetic regulation of individual proteins in relA + and relA strains of Escherichia coli during amino acid starvation. Mol Gen Genet 149:279–289
Said B, Cole JR, Nomura M (1988) Mutational analysis of the L1 binding site of 238 rRNA in E. coli. Nucleic Acids Res 16:10529–10545
Sanger F, Nicklen S, Coulson A (1977) DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci USA 74:5463–5467
Skouv J, Schnier J, Rasmussen MD, Subramanian AR, Pedersen S (1990) Ribosomal protein S1 of Escherichia coli is the effector for the regulation of its own synthesis. J Biol Chem 265:17044–17049
Sørensen MA, Kurland CG, Pedersen S (1989) Codon usage determines the translation rate in Escherichia coli. J Mol Biol 207:365–377
Takeshita S, Sato M, Toba M, Masahashi W, Hashimoto-Gotoh T (1987) High copy-number and low-copy-number plasmid vectors for lacZ α-complementation and chloramphenicol- or kanamycin-resistance selection. Gene 61:63–74
Thomas MS, Nomura M (1987) Translational regulation of the L11 ribosomal protein operon of Escherichia coli: mutations that define the target site for repression by L1. Nucleic Acids Res 15:3085–3096
Ullmann A, Jacob F, Monod J (1967) On the subunit structure of wild type versus complemented β-galactosidase of Escherichia coli. J Mol Biol 24:339–371
Vind J, Sorensen MA, Rasmussen MD, Pedersen S (1993) The synthesis of proteins in Escherichia coli is limited by the concentration of free ribosomes: Expression from reporter genes does not always reflect functional mRNA levels. J Mol Biol, in press
Author information
Authors and Affiliations
Additional information
Communicated by K. Isono
Rights and permissions
About this article
Cite this article
Rasmussen, M.D., Sørensen, M.A. & Pedersen, S. Isolation and characterization of mutants with impaired regulation of rpsA, the gene encoding ribosomal protein S1 of Escherichia coli . Molec. Gen. Genet. 240, 23–28 (1993). https://doi.org/10.1007/BF00276879
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00276879