Über die Frage der Mehrdeutigkeit des genetischen Codes, untersucht am Hüllenprotein des Tabakmosaikvirus
- 19 Downloads
Summary
An investigation has been made of whether ambiguity of the genetic code, i.e. variation in the translation of the genetic message produced by some external factors, occurs in tobacco plants infected with tobacco mosaic virus (TMV). This effect ist known to occur in bacterial systems.
The following experiments have been done: a) TMV-vulgare infected plants were kept at five different temperatures between the minimum (12°C) and maximum (37°C) of the virus multiplication. b) TMV-A14 was grown in leaves in the presence of high concentrations of each of the following three cations: streptomycin, spermine, Mg++. c) Plants infected with the TMV mutant Ni 1927 were kept under the same conditions as in and b.
After isolation of the virus the following proteinchemical methods were applied to the virus preparations which were grown under the eight conditions mentioned above: a) Amino acid analyses of the whole coat protein of TMV vulgare, b) separation of the RNA from the coat protein of vulgare and A 14, digestion of the proteins with trypsin, isolation of all tryptic peptides by column and paper chromatography, hydrolysis and analysis of the amino acid composition of each peptide, c) quantitative determinations of the terminal amino acids split off by treatment of Ni 1927 with carboxypeptidase A.
The analyses of all virus preparations gave the same results: within the experimental errors (1–2% and 5% depending on the method) there is no variation in the amino acid compositions of the tryptic peptides as a consequence of the various polycations or temperatures. The same result has been found with X-protein isolated from leaves in which the virus was synthesized in the presence of streptomycin.
From the foregoing analyses it was concluded that translation of the genetic information into the amino acid sequence of TMV protein is influenced, if at all, to such a low extent that this effect cannot be found by the current methods of proteinchemistry.
Preview
Unable to display preview. Download preview PDF.
Literatur
- Bretscher, M. S., andM. Grunberg-Manago: Polynucleotide-directed protein synthesis using an E. coli cell free system. Nature (Lond.)195, 283–284 (1962).Google Scholar
- Davies, J., W. Gilbert, andL. Gorini: Streptomycin, suppression and the code. Proc. nat. Acad. Sci. (Wash.)51, 883–890 (1964).Google Scholar
- Friedman, S. M., andJ. B. Weinstein: Lack of fidelity in the translation of synthetic polyribonucleotides. Proc. nat. Acad. Sci. (Wash.)52, 988–996 (1964).Google Scholar
- Gorini, L., andE. Kataja: Phenotypic repair by streptomycin of defective genotypes in E. coli. Proc. nat. Acad. Sci. (Wash.)51, 487–493 (1964).Google Scholar
- Lengyel, P., J. F. Speyer, andS. Ochoa: Synthetic polynucleotides and the amino acid code. Proc. nat. Acad. Sci. (Wash.)47, 1936–1942 (1961).Google Scholar
- Melchers, G.: Die biologische Untersuchung des “Tomatenvirus Dahlem 1940”. Biol. Zbl.60, 527–537 (1940).Google Scholar
- Nirenberg, M. W., andJ. H. Matthaei: The dependence of cell-free protein synthesis in E. coli upon naturally occurring or synthetic polyribonucleotides. Proc. nat. Acad. Sci. (Wash.)47, 1588–1602 (1961).Google Scholar
- Sengbusch, P. v., andH. G. Wittmann: Serological and physico-chemical properties of the wild strain and two mutants of tobacco mosaic virus with the same amino acid exchange in different positions of the protein chain. Biochem. biophys. Res. Commun.18, 780–787 (1965).Google Scholar
- Szer, W., andS. Ochoa: Complexing ability and coding properties of synthetic polynucleotides. J. molec. Biol.8, 823–834 (1964).Google Scholar
- Takahashi, W. N., andM. Ishii: An abnormal protein associated with TMV infection. Nature (Lond.)169, 419–420 (1952).Google Scholar
- Valentine, R. C., andN. D. Zinder: Phenotypic repair of RNA-bacteriophage mutants by streptomycin. Science144, 1458–1459 (1964).Google Scholar
- Wittmann, H. G.: Proteinuntersuchungen an Mutanten des Tabakmosaikvirus als Beitrag zum Problem des genetischen Codes. Z. Vererbungsl.93, 491–530 (1962).Google Scholar
- —: Proteinanalysen von chemisch induzierten Mutanten des Tabakmosaikvirus. Z. Vererbungsl.95, 333–344 (1964).Google Scholar