Cold-sensitive growth of a mutants ofEscherichia coli with an altered ribosomal protein S8: Analysis of revertants
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26 cold-resistant revertants of a cold-sensitiveEscherichia coli mutant with an altered ribosomal protein S8 were analyzed for their ribosomal protein pattern by two-dimensional polyacrylamide gel electrophoresis. It was found that 16 of them had acquired the apparent wild-type form of protein S8, one exhibits a more strongly altered S8 than the original mutant and two revertants regained the wild-type form of S8 and, in addition, possess alterations in protein L30. The ribosomes of the residual revertants showed no detectable difference from those of the parental S8 mutant.
The mutation leading to the more strongly altered S8 was genetically not separable from the primary S8 mutation; this indicates that both mutations are very close to each other or at the same site. The structural gene for ribosomal protein L30 was mapped relative to two other ribosomal protein genes (for proteins S5 and S8) by the aid of one of the L30 mutants: The relative order obtained is:aroE....rpmD(L30)....rpsE(S5)....rpsH(S8)....
THe L30 mutation impairs growth and ribosomal assembly at 20°C and is therefore the first example of a mutant with a defined 50S alteration that has (partial) cold-sensitive ribosome assembly. A double mutant was constructed which possesses both the S8 and the L30 mutations. It was found that the L30 mutation had a slight antagonistic effect on the growth inhibition caused by the S8 mutation. Thus the L30 mutants might have possibly arisen from the original S8 mutants first as S8/L30 double mutants which was followed by the loss of the original S8 lesion.
KeywordsElectrophoresis Polyacrylamide Protein Gene Ribosomal Protein Double Mutant
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- Bachmann, B.J., Low, K.B., Taylor, A.L.: Recalibrated linkage map ofEscherichia coli K 12. Bact. Rev.40 116–167 (1976)Google Scholar
- Buckel, P., Piepersberg, W., Böck, A.: Suppression of aminoacyl-tRNA synthetase mutations by ribosomal mutations: A possible mechanism. Molec. gen. Genet.149, 51–61 (1976)Google Scholar
- Guthrie, Ch., Nashimoto, H., Nomura, M.: Structure and function ofE. coli ribosomes, VIII. Cold-sensitive mutants defective in ribosomal assembly. Proc. nat. Acad. Sci. (Wash.)63, 384–391 (1969)Google Scholar
- Hardy, S.J.S., Kurland, C.G., Voynow, P., Mora, G.: The ribosomal proteins ofEscherichia coli I. Purification of the 30S proteins. Biochem.8, 2897–2905 (1969)Google Scholar
- Kaltschmidt, E., Wittmann, H.G.: Ribosomal proteins VII. Two-dimensional polyacrylamide gel electrophoresis for fingerprinting of ribosomal proteins. Analyt. Biochem.36, 401–412 (1970)Google Scholar
- Nashimoto, H., Uchida, H.: Late steps in the assembly of 30S ribosomal proteinsin vivo in a spectinomycin-resistant mutant ofEscherichia coli. J. molec. Biol.96, 443–453 (1975)Google Scholar
- Nierhaus, K.H., Bordasch, K., Homann, H.E.: Ribosomal proteins XLIII.In vivo assembly ofEscherichia coli ribosomal proteins. J. molec. Biol.74, 587–597 (1973)Google Scholar
- Nomura, M., Held, W.A.: Reconstitution of ribosomes: Studies of ribosome structure, function and assembly. In: Ribosomes. Cold Spring Harbor Monograph Series, pp. 193–223. New York: Cold Spring Harbor Laboratory 1974Google Scholar
- Nomura, M., Jaskunas, S.R.: Organisation of genes for ribosomal RNA, ribosomal proteins, protein elongation factors and RNA polymerase subunuts inEscherichia coli. In: Alfred Benzon symposium IX, Control of ribosome synthesis, pp. 191–204. Copenhagen Munksgaard: 1976Google Scholar
- Piepersberg, W., Böck, A., Wittmann, H.G.: Effect of different mutations in ribosomal protein S5 ofEscherichia coli on translational fidelity. Molec. gen. Genet.140, 91–100 (1975b)Google Scholar
- Piepersberg, W., Böck, A., Yaguchi, M., Wittmann, H.G.: Genetic position and amino acid replacements of several mutations in ribosomal protein S5 fromEscherichia coli. Molec. gen. Genet.143, 43–52 (1975a)Google Scholar
- Wittmann, H.G., Stöffler, G., Geyl, D., Böck, A.: Alteration of ribosomal proteins in revertants of a valyl-tRNA synthetase mutant ofEscherichia coli. Molec. gen. Genet.141, 317–329 (1975a)Google Scholar
- Wittmann, H.G., Yaguchi, M., Piepersberg, W., Böck, A. Direction of transcription of two ribosomal protein genes inEscherichia coli. J. molec. Biol.98, 827–829 (1975b)Google Scholar
- Zimmermann, R.A.: RNA-protein interactions in the ribosome. In: Ribosomes. Cold Spring Harbor Monograph Series, pp. 225–269. New York Cold Spring Harbor Laboratory 1974Google Scholar