Summary
A heat sensitive mutant of E. coli has been analyzed. A shift to restrictive temperature leads to an accumulation of ppGpp and pppGpp in both the parental and the mutant strains (both are relA +). The pool of these compounds is shown to decrease with time after the temperature shift in the case of the parental strain, but remains at the same elevated level in the case of the mutant. The temperature shift of the mutant leads to an apparent reduction of stable RNA synthesis; this inhibition can be released by chloroamphenicol or tetracycline. Gross protein synthesis is more or less unaffected at restrictive temperature. In the parental strain little effect is seen on RNA and protein synthesis after the temperature shift. A relA derivative of the mutant does not show the same inhibition of RNA synthesis at high temperature. Sedimentation analysis suggests that mutant 70S ribosomes are more stable, when exposed to a lowered Mg2+ concentration, than are 70S ribosomes from the parental strain. In addition, the relative amounts of the two forms of ribosomal protein S6, which can be obtained on DEAE chromatography (Held et al., 1973), are significantly changed in the mutant.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Cashel, M.: The control of ribonucleic acid synthesis in Escherichia coli IV. Relevance of unusual phosphorylated compounds from amino acid starved stringent strain. J. biol. Chem. 244, 3133–3141 (1969)
Gros, F., Hiatt, H., Gilbert, W., Kurland, C.G., Risebrough, R.W., Watson, J.D.: Unstable ribonucleic acid revealed by pulse labelling of Escherichia coli. Nature (Lond.) 190, 581–585 (1961)
Hardy, S.J.S., Kurland, C.G., Voynow, P., Mora, G.: The ribosomal proteins of Escherichia coli. I. Purification of the 30S ribosomal proteins. Biochemistry 8, 2897–2905 (1969)
Haseltine, W.A., Block, R.: Synthesis of guanosinetetra and pentaphosphate requires the presence of a codon specific, uncharged transfer ribonucleic acid in the acceptor site of ribosomes. Proc. nat. Acad. Sci. (Wash.) 70, 1564–1568 (1973)
Held, W.A., Mizushima, S., Nomura, M.: Reconstitution of Escherichia coli 30S ribosomal subunits from purified molecular compounds. J. biol. Chem. 248, 5720–5730 (1973)
Hitz, M., Schäfer, D., Wittman-Liebold, B.: Primary structure of ribosomal protein S6 from the wild type and a mutant of Escherichia coli. FEBS Letters 56, 259–262 (1975)
Isaksson, L.A., Philips, J.M.: Studies on microbial RNA V. A comparison of the in vivo metylated compounds of ribosomal RNA from Escherichia coli and Saccaromyces cerevisiae. Biochim. biophys. Acta (Amst.) 155, 63–71 (1968)
Isaksson, L.A., Sköld, S.E., Sköldebrand, J., Takata, R.: A procedure for isolation of spontaneous mutants with temperature sensitive synthesis of RNA and/or protein. Molec. gen. Genet. 156, 233–237 (1977)
Isaksson, L.A., Takata, R.: The temperature sensitive mutant 72c. I. Pleiotropic growth behaviour and changed response to some antibiotics and mutations in the transcription and translation apparatus. Molec. gen. Genet. 161, 9–14 (1978)
Kaldsmidt, E., Wittmann, H.G.: Ribosomal proteins VII. Two-dimensional polyacrylamide gel electrophoresis for fingerprinting of ribosomal proteins. Analyt. Biochem. 36, 401–412 (1970)
Lazzarini, R.A., Cashel, M., Gallant, J.: On the regulation of guanosine tetraphosphate levels in stringent and relaxed strains of Escherichia coli. J. biol. Chem. 246, 4381–4385 (1971)
Lund, E., Kjeldgard, N.O.: Metabolism of guanosine tetraphosphate in Escherichia coli. Europ. J. Biochem. 28, 316–326 (1972)
Muto, A., Kimura, A., Osawa, S.: Effects of some antibiotics on the stringent control of RNA synthesis in Escherichia coli. Molec. gen. Genet. 139, 321–327 (1975)
Ny, T., Björk, G.R.: Stringent regulation of the synthesis of a transfer ribonucleic acid biosynthetic enzyme: transfer ribonucleic acid (m5U) methyltransferase from Escherichia coli. J. Bact. 130, 635–641 (1977)
Peacock, A.C., Dingman, C.W.: Resolution of multiple ribonucleic acid species by polyacrylamide gel electrophoresis. Biochemistry 6, 1818–1827 (1968)
Pedersen, F.S., Lund, E., Kjeldgaard, N.O.: Codon specific tRNA dependent in vitro synthesis of ppGpp and pppGpp. Nature (Lond.) New Biol. 243, 13–15 (1973)
Author information
Authors and Affiliations
Additional information
Communicated by E. Bautz
Rights and permissions
About this article
Cite this article
Takata, R., Isaksson, L.A. The temperature sensitive mutant 72c. Molec. Gen. Genet. 161, 15–21 (1978). https://doi.org/10.1007/BF00266610
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00266610