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. 1982 Aug;151(2):976–982. doi: 10.1128/jb.151.2.976-982.1982

Mutations in genes cpxA and cpxB of Escherichia coli K-12 cause a defect in acetohydroxyacid synthase I function in vivo.

A Sutton, T Newman, J McEwen, P M Silverman, M Freundlich
PMCID: PMC220350  PMID: 7047501

Abstract

Mutations in Escherichia coli genes cpxA and cpxB together cause a temperature-sensitive defect in isoleucine and valine syntheses that is related specifically to acetohydroxyacid synthase I. This enzyme catalyzes the first pair of homologous reactions required for the synthesis of these two amino acids. At both permissive and nonpermissive temperatures, mutant cells containing ilvB (the structural gene for acetohydroxyacid synthase I) cloned in a derivative of plasmid pBR322 synthesized comparable amounts of ilvB mRNA and contained several times the enzyme activity normally required to sustain exponential growth, yet these cells remained temperature sensitive for growth in the absence of isoleucine and valine. These observations suggest that the primary effect of the cpx mutations is to block enzyme function in vivo. The enzyme was unstable in mutant cells at growth temperatures above 37 degrees C, but this instability appeared to be a secondary effect on the cpx mutations.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Blatt J. M., Jackson J. H. Enhanced allosteric regulation of threonine deaminase and acetohydroxy acid synthase from Escherichia coli in a permeabilized-cell assay system. Biochim Biophys Acta. 1978 Sep 11;526(1):267–275. doi: 10.1016/0005-2744(78)90311-x. [DOI] [PubMed] [Google Scholar]
  2. Blatt J. M., Pledger W. J., Umbarger H. E. Isoleucine and valine metabolism in Escherichia coli. XX. Multiple forms of acetohydroxy acid synthetase. Biochem Biophys Res Commun. 1972 Jul 25;48(2):444–450. doi: 10.1016/s0006-291x(72)80071-8. [DOI] [PubMed] [Google Scholar]
  3. Butlin J. D., Cox G. B., Gibson F. Oxidative phosphorylation in Escherichia coli K-12: the genetic and biochemical characterisations of a strain carrying a mutation in the uncB gene. Biochim Biophys Acta. 1973 Feb 22;292(2):366–375. doi: 10.1016/0005-2728(73)90043-1. [DOI] [PubMed] [Google Scholar]
  4. Childs G. J., Freundlich M. Transcriptional control of the isoleucine-valine messenger RNA's in E. coli K-12. Mol Gen Genet. 1975 Jun 19;138(3):257–268. doi: 10.1007/BF00269352. [DOI] [PubMed] [Google Scholar]
  5. Cronenwett C. S., Wagner R. P. Over-all synthesis of isoleucine by membrane fractions of Salmonella typhimurium. Proc Natl Acad Sci U S A. 1965 Dec;54(6):1643–1650. doi: 10.1073/pnas.54.6.1643. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. DAVIS B. D., MINGIOLI E. S. Mutants of Escherichia coli requiring methionine or vitamin B12. J Bacteriol. 1950 Jul;60(1):17–28. doi: 10.1128/jb.60.1.17-28.1950. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Downie J. A., Gibson F., Cox G. B. Membrane adenosine triphosphatases of prokaryotic cells. Annu Rev Biochem. 1979;48:103–131. doi: 10.1146/annurev.bi.48.070179.000535. [DOI] [PubMed] [Google Scholar]
  8. FREUNDLICH M., BURNS R. O., UMBARGER H. E. Control of isoleucine, valine, and leucine biosynthesis. I. Multivalent repression. Proc Natl Acad Sci U S A. 1962 Oct 15;48:1804–1808. doi: 10.1073/pnas.48.10.1804. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Gray J. E., Patin D. W., Calhoun D. H. Identification of the protein products of the rrnC, ilv, rho region of the Escherichia coli K-12 chromosome. Mol Gen Genet. 1981;183(3):428–436. doi: 10.1007/BF00268761. [DOI] [PubMed] [Google Scholar]
  10. Grimminger H., Umbarger H. E. Acetohydroxy acid synthase I of Escherichia coli: purification and properties. J Bacteriol. 1979 Feb;137(2):846–853. doi: 10.1128/jb.137.2.846-853.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  12. Lawther R. P., Calhoun D. H., Adams C. W., Hauser C. A., Gray J., Hatfield G. W. Molecular basis of valine resistance in Escherichia coli K-12. Proc Natl Acad Sci U S A. 1981 Feb;78(2):922–925. doi: 10.1073/pnas.78.2.922. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. McEwen J., Silverman P. Chromosomal mutations of Escherichia coli that alter expression of conjugative plasmid functions. Proc Natl Acad Sci U S A. 1980 Jan;77(1):513–517. doi: 10.1073/pnas.77.1.513. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. McEwen J., Silverman P. Genetic analysis of Escherichia coli K-12 chromosomal mutants defective in expression of F-plasmid functions: identification of genes cpxA and cpxB. J Bacteriol. 1980 Oct;144(1):60–67. doi: 10.1128/jb.144.1.60-67.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. McEwen J., Silverman P. Mutations in genes cpxA and cpxB of Escherichia coli K-12 cause a defect in isoleucine and valine syntheses. J Bacteriol. 1980 Oct;144(1):68–73. doi: 10.1128/jb.144.1.68-73.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Newman T. C., Levinthal M. A new map location for the ilvB locus of Escherichia coli. Genetics. 1980 Sep;96(1):59–77. doi: 10.1093/genetics/96.1.59. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. O'Neill J. P., Freundlich M. Effect of cyclopentaneglycine on metabolism in Salmonella typhimurium. J Bacteriol. 1972 Aug;111(2):510–515. doi: 10.1128/jb.111.2.510-515.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. O'Neill J. P., Freundlich M. Two forms of biosynthetic acetohydroxy acid synthetase in Salmonella typhimurium. Biochem Biophys Res Commun. 1972 Jul 25;48(2):437–443. doi: 10.1016/s0006-291x(72)80070-6. [DOI] [PubMed] [Google Scholar]
  19. Rizzino A. A., Bresalier R. S., Freundlich M. Derepressed levels of the isoleucine-valine and leucine enzymes in his T 1504, a strain of Salmonella typhimurium with altered leucine transfer ribonucleic acid. J Bacteriol. 1974 Feb;117(2):449–455. doi: 10.1128/jb.117.2.449-455.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Silverman P. M. Gene cpxA is a new addition to the linkage map of Escherichia coli K-12. J Bacteriol. 1982 Apr;150(1):425–428. doi: 10.1128/jb.150.1.425-428.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]

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