Summary
Three spontaneous fol regulatory mutants contain dihydrofolate reductase molecules which differ in physical properties from enzymes of their parent strains. The enzymes were purified over 100-fold by affinity chromatography and were shown to differ in vitro in thermolability and in affinity for trimethoprim, a competitive inhibitor of the enzyme. These results indicate that some fol regulatory mutations occur in the structural gene for dihydrofolate reductase.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Goldberger, R.F.: Autogenous regulation of gene expression. Science 183, 810–816. (1974)
Hercules, K., Schveiger, M., Sauerbier, W.: Cleavage by RNase III Converts T3 and T7 Early Precursor RNA into translatable message. Proc. nat. Acad. Sci. (Wash.) 74, 840–844 (1974)
Kaufman, B.T.: Methotrexate-agarose in the purification of dihydrofolate reductase. Methods in Enzymology 34, 272–218. New York: Academic Press 1974
Lodish, H.F.: Secondary structure of bacteriophage f2 ribonucleic acid and the initiation of in vtiro protein biosynthesis. J. molec. Biol. 50, 689–702 (1970)
Poe, M., Greenfield, N.J., Hirshfield, J.M., Williams, M.N., Hoogsteen, K.: Dihydrofolate reductase. Purification and properties of the enzyme from an amethopterin-resistant mutant of Escherichia coli. Biochem. 11, 1023–1030 (1972)
Ray, P.N., Pearson, M.L.: Evidence for post-transcriptional control of the morphogenetic genes of bacteriophage lambda. J. molec. Biol. 85, 163–175 (1974)
Sheldon, R., Brenner, S.: Regulatory mutants of dihydrofolate reductase in Escherichia coli K12. Molec. gen. Genet. 147, 91–97 (1976)
Singer, B.S., Gold, L.: A mutation that confers temperature sensitivity on the translation of rIIB in bacteriophage T4. J. molec. Biol. 103, 627–646 (1976)
Sirotnak, F.M., Hachtel, S.L.: Increased dihydrofolate reductase synthesis in Diplococcus pneumoniae following translatable alteration of the structural gene. I. genotype derivation and recombinational analyses. Genetics 61, 293–312. (1969)
Sirotnak, F.M., Hachtel, S.L., Williams, W.A.: Increased dihydrofolate reductase synthesis in Diplococcus pneumoniae following translatable alteration of the structural gene. II. Individual and dual effects on the properties and rate of synthesis of the enzyme. Genetics 61, 313–326 (1969)
Sirotnak, F.M., McCuen, R.W.: Hyperproduction of dihydrofolate reductase in Diplococcus pneumoniae after mutation in the structural gene. Evidence for an effect at the level of transcription. Genetics 74, 543–556 (1973)
Smith, J.D.: Mutants which allow accumulation of tRNAtyr precursor molecules. Brookhaven Symposium 26, 1–11 (1974)
Author information
Authors and Affiliations
Additional information
Communicated by W. Arber
Rights and permissions
About this article
Cite this article
Sheldon, R. Altered dihydrofolate reductase in fol regulatory mutants of Escherichia coli K12. Molec. gen. Genet. 151, 215–219 (1977). https://doi.org/10.1007/BF00338697
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00338697