Summary
Genetic mapping experiments have established that two recently isolated valine-resistant mutants of the K-12 strain of Escherichia coli have lesions lying between ilvE and rbs. These lesions allowed expression of the ilvG gene, specifying the valine-insensitive acetohydroxy acid synthase (synthase II) and an increased expression of the ilvEDA operon. In this respect, they resembled an earlier described ilvO lesion that was reported to lie between ilvA and ilvC. All three lesions were cis-dominant in cis-trans tests. Reexamination of the earlier studied ilvO lesion revealed that it, too, lies between ilvE and rbs. Valine-sensitive derivatives with lesions presumed to be in ilvG were selected from each of the valine-resistant strains. In two of the valine-resistant strains, the ilvG mutations were on the rbs side of ilvO, indicating a gene order rbs-ilvG-ilvO-ilvE-ilvD-ilvA-ilvC. In one of the recently isolated valine-resistant stocks, however, the apparent ilvG mutation was found to be between ilvE and the aline resistance marker. This finding suggests that either ilvO and ilvG mutations are interspersed or there is another locus, ilvR, that behaves phenotypically like ilvO and which lies between ilvG and rbs.
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Avitabile, A., Carlomagno-Cerillo, M.S., Favre, R., Blasi, F.: Isolation of transducing phages for the histidine and isoleucinevaline operons in Escherichia coli K-12. J. Bacteriol. 112, 40–47 (1972)
Baez, M., Patin, D.W., Calhoun, D.H.: Deletion mapping of the ilvGOEDAC genes of Escherichia coli K-12. Mol. Gen. Genet. 169, 289–297 (1979)
Bertani, G.: Studies on lysogenesis. I. The mode of phage liberation by lysogenic Escherichia coli. J. Bacteriol. 62, 293–300 (1951)
Cohen, B.M., Jones, E.: New map location of ilvO in Escherichia coli. Genetics 83, 201–225 (1976)
Curtiss, R., Charamella, L.J., Berg, C.M., Harris, P.E.: Kinetic and genetic analysis of D-cycloserine inhibition and resistance in Escherichia coli. J. Bacteriol. 90, 1238–1250 (1965)
Davis, B.D., Mingioli, E.S.: Mutants of Escherichia coli requiring methionine or vitamin B12. J. Bacteriol. 60, 17–28 (1950)
Duggan, D.E., Wechsler, J.A.: An assay for transaminase B enzyme activity in Escherichia coli K-12. Analyt. Biochem. 51, 67–79 (1973)
Favre, R., Wiater, A., Puppo, S., Iaccarino, M., Noelle, R., Freundlich, M.: Expression of a valine resistant acetolactate synthase activity mediated by the ilvO and ilvG genes of Escherichia coli K-12. Mol. Gen. Genet. 143, 243–252 (1976)
Friedemann T.E., Haugen, G.E.: Pyruvic acid. II. The determination of keto acids in blood and urine. J. Biol. Chem. 147, 415–442 (1943)
Guardiola, J., DeFelice, M., Lamberti, A., Iaccarino, M.: The acetolactate synthase isozymes of Escherichia coli K-12. Mol. Gen. Genet. 156, 17–25 (1977)
Howe, M.M., Bade, E.G.: Molecular biology of bacteriophage Mu. Science 190, 624–632 (1975)
Kline, E.L., Brown, C.S., Coleman, W.G., Jr., Umbarger, H.E.: Regulation of isoleucine-valine biosynthesis in an ilvDAC deletion strain of Escherichia coli K-12. Biochem. Biophys. Res. Commun. 57, 1144–1151 (1974)
Louarn, J., Funderburgh, M., Bird, R.E.: More precise mapping of the replication origin in Escherichia coli K-12. J. Bacteriol. 120, 1–5 (1974)
Lowry, O.H., Rosebrough, N.J., Farr, A.L.: Protein measurement with the Folin phenol reagent. J. Biol. Chem. 193, 265–275 (1951)
Marsh, N.J., Duggan, D.E.: Ordering of mutant sites in the isoleucine-valine genes of Escherichia coli by use of merogenotes derived from F14: a new procedure for fine-structure mapping. J. Bacteriol. 109, 730–740 (1972)
McGilvray, D., Umbarger, H.E.: Regulation of transaminase C synthesis in Escherichia coli: conditional leucine auxotrophy. J. Bacteriol. 120, 715–723 (1974)
Pledger, W.J., Umbarger, H.E.: Isoleucine and valine metabolism in Escherichia coli. XXI. Mutations affecting depression and valine resistance. J. Bacteriol. 114, 183–194 (1973a)
Pledger, W.J., Umbarger, H.E.: Isoleucine and valine metabolism in Escherichia coli. XII. A pleiotropic mutation affecting induction of isomeroreductase activity. J. Bacteriol. 114, 195–207 (1973b)
Ramakrishnan, T., Adelberg, E.A.: Regulatory mechanisms in the biosynthesis of isoleucine and valine. II. Identification of two operator genes. J. Bacteriol. 89, 654–660 (1965)
Rosner, J.L.: Formation, induction, and curing of bacteriophage P1 lysogens. Virology 49, 679–689 (1972)
Smith, J.M., Smolin, D.E., Umbarger, H.E.: Polarity and the regulation of the ilv gene cluster in Escherichia coli strain K-12. Mol. Gen. Genet. 148, 111–124 (1976)
Smith, J.M., Umbarger, H.E.: Characterization of fusions between the lac operon and the ilv gene cluster in Escherichia coli: ilvC-lac fusions. J. Bacteriol. 132, 870–875 (1977)
Westerfeld, W.W.: A colorimetric determination of blood acetoin. J. Biol. Chem. 161, 495–502 (1945)
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Smith, J.M., Smith, F.J. & Umbarger, H.E. Mutations affecting the formation of acetohydroxy acid synthase II in Escherichia coli K-12. Molec. Gen. Genet. 169, 299–314 (1979). https://doi.org/10.1007/BF00382276
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DOI: https://doi.org/10.1007/BF00382276