Summary
A prediction based on the model forN-gene function of bacteriophage λ proposed by Roberts (1971) is confirmed by showing that a λN − double mutant is able to grow in strains ofE. coli with defective rho transcription termination factors. The burst sizes for λN − in these strains range from 5 to 24% the burst sizes for λN + in the same strain. This low level of suppression is also evident in the levels of synthesis of the λ exonuclease and is consistent with other evidence that the defect in the rho factors of these strains is only partial. These strains do not suppress the effects of mutations in genesO, P andQ of λ nor in genes30 and43 of bacteriophage T4. The lack of suppression of λQ − is significant because theQ-gene product, like theN-gene product, is believed to function as an anti-terminator of λ transcription but at termination sites that may not require rho factor action.
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Anderson, L.E., McClure, W. O.: An improved scintillation cocktail of high-solubilizing power. Anal. Biochem.51, 173 (1973)
Beckwith, J.: Restoration of operon activity by suppressors. Biochim. biophys. Acta (Amst.)76, 162 (1963)
Belfort, M., Oppenheim, A.B.: Efficient suppression of the requirement for N-function of bacteriophage λ by arho-defectiveE. coli suA mutant. Molec. gen. Genet.148, 171 (1976)
Blattner, F.R., Dahlberg, J.E.: RNA synthesis startpoints in bacteriophage λ: Are the promoter and operator transcribed? Nature (Lond.) New Biol237, 227 (1972)
Brunel, F., Davidson, J.: Bacterial mutants able to partly suppress the effect ofN mutations in bacteriophage λ. Molec. gen. Genet.136, 167 (1975)
Carter, T., Newton, A.: New polarity suppressors inE. coli: Suppression and messenger RNA stability. Proc. nat. Acad. Sci. (Wash.)68, 2962 (1971)
Das, A., Court, D., Adhya, S.: Isolation and characterization of conditional lethal mutants ofE. coli defective in transcription termination factor rho. Proc. nat. Acad. Sci. (Wash.)73, 1959 (1976)
Dambly, C., Court, D., Brachet, P.: Specificity of polarity suppression inE. coli: Correction of defects in gene N, but not in gene Q of phage λ. Molec. gen. Genet.148, 175 (1976)
Echols, H.: Regulation of lytic development. In: The bacteriophage lambda (ed., Hershey, A.D.), pp. 247–270. Cold Spring Harbor, New York: Cold Spring Harbor Laboratory 1971)
Friedman, D.I., Wilgus, G.S., Mural, R.S.: Gene N regulator function of phage λimm21: evidence that a site ofN action differs from a site ofN recognition. J. molec. Biol.81, 505 (1973)
Grimley, C.: Altered transcription termination factor rho fromsuA strain ofE. coli. Masters dissertation Indiana University, Bloomington, Indiana (1976)
Holmes, G. E.: Suppression of phage nonsense and temperature-sensitive mutants by ansuA mutant inE. coli. Nature (Lond.)250, 73 (1974)
Inoko, H., Imai, M.: Isolation and genetic characterization of thenitA mutants ofE. coli affecting the termination factor rho. Molec. gen. Genet.143, 211 (1976)
Inoko, H., Shigesada, K., Imai, M.: Isolation and characterization of conditional lethal rho mutants ofE. coli. Proc. nat. Acad. Sci. (Wash.)74, 1162 (1977)
Korn, L.S., Yanofsky, C.: Polarity suppressors defective in transcription termination at the attenuator of the tryptophan operon ofE. coli have altered rho factor. J. molec. Biol.106, 231 (1976)
Kuwano, M., Schlessinger, D., Morse, D.E.: Loss of dispensable endonuclease activity in relief of polarity bysuA. Nature (Lond.) New Biol.231, 214 (1971)
Lowry, O.H., Rosebrough, N.J., Fan, A.L., Randall, R.J.: Protein measurements with the Folin phenol reagent. J. biol. Chem.193, 265 (1951)
McMacken, R., Mantei, N., Butler, B., Joyner, A., Echols, H.: The effect of mutations in thecII andcIII genes of bacteriophage λ on macromolecular synthesis in infected cells. J. molec. Biol.49, 639 (1970)
Morse, D.E., Guertin, M.: AmbersuA mutations which relieve polarity. J. molec. Biol.63, 605 (1972)
Ratner, D.: Evidence that mutations in thesuA polarity suppressing gene directly affect termination factor rho. Nature (Lond.)259, 151 (1976)
Richardson, J.P.: Mechanism of ethidium bromide inhibition of RNA polymerase. J. molec. Biol.78, 703 (1975)
Richardson, J.P., Grimley, C., Lowery, C.: Transcription termination factor rho activity is altered inE. coli withsuA gene mutations. Proc. nat. Acad. Sci. (Wash.)72, 1725 (1975)
Roberts, J.W.: Termination factor for RNA synthesis. Nature (Lond.)224, 1168 (1969)
Roberts, J.W.: Thep factor: Termination and anti-termination in lambda. Cold Spr. Harb. Symp. quant. Biol.35, 121 (1971)
Roberts, J.W.: Transcription termination and late control in phage lambda. Proc. nat. Acad. Sci (Wash.)72, 3300 (1975)
Roberts, J.W.: Transcription termination and its control inE. coli. In: RNA polymerase (eds. Losick, R., Chamberlin, M.), pp. 247–271. Cold Spring Harbor, New York: Cold Spring Harbor Laboratory 1976)
Rosenberg, M., Weissman, S., de Crombrugghe, B.: Termination of transcription in bacteriophage λ. J. biol. Chem.250, 4755 (1975)
Steinberg, C.M., Edgar, R.S.: A critical test of a current theory of genetic recombination in bacteriophage. Genetics47, 187 (1962)
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Richardson, J.P., Fink, P., Blanchard, K. et al. Bacteria with defective rho factors suppress the effects ofN mutations in bacteriophage λ. Molec. Gen. Genet. 153, 81–85 (1977). https://doi.org/10.1007/BF01035999
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DOI: https://doi.org/10.1007/BF01035999