PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of jbacterPermissionsJournals.ASM.orgJournalJB ArticleJournal InfoAuthorsReviewers
 
J Bacteriol. 1977 April; 130(1): 429–440.
PMCID: PMC235221

Escherichia coli mutants deficient in the aspartate and aromatic amino acid aminotransferases.

Abstract

Two new mutations are described which, together, eliminate essentially all the aminotransferase activity required for de novo biosynthesis of tyrosine, phenylalanine, and aspartic acid in a K-12 strain of Escherichia coli. One mutation, designated tyrB, lies at about 80 min on the E. coli map and inactivates the "tyrosine-repressible" tyrosine/phenylalanine aminotransferase. The second mutation, aspC, maps at about 20 min and inactivates a nonrespressible aspartate aminotransferase that also has activity on the aromatic amino acids. In ilvE- strains, which lack the branched-chain amino acid aminotransferase, the presence of either the tyrosine-repressible aminotransferase or the aspartate aminotransferase is sufficient for growth in the absence of exogenous tyrosine, phenylalanine, or aspartate; the tyrosine-repressible enzyme is also active in leucine biosynthesis. The ilvE gene product alone can reverse a phenylalanine requirement. Biochemical studies on extracts of strains carrying combinations of these aminotransferase mutations confirm the existence of two distinct enzymes with overlapping specificities for the alpha-keto acid analogues of tyrosine, phenylalanine, and aspartate. These enzymes can be distinguished by electrophoretic mobilities, by kinetic parameters using various substrates, and by a difference in tyrosine repressibility. In extracts of an ilvE- tyrB- aspC- triple mutant, no aminotransferase activity for the alpha-keto acids of tyrosine, phenylalanine, or aspartate could be detected.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (2.0M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • ADELBERG EA, UMBARGER HE. Isoleucine and valine metabolism in Escherichia coli. V. alpha-Ketoisovaleric acid accumulation. J Biol Chem. 1953 Nov;205(1):475–482. [PubMed]
  • Brown KD, Somerville RL. Repression of aromatic amino acid biosynthesis in Escherichia coli K-12. J Bacteriol. 1971 Oct;108(1):386–399. [PMC free article] [PubMed]
  • Chesne S, Pelmont J. Glutamate-oxaloacétate transaminase d'Escherichia coli. I. Purification et spécificité. Biochimie. 1973;55(3):237–244. [PubMed]
  • Clark AJ. Recombination deficient mutants of E. coli and other bacteria. Annu Rev Genet. 1973;7:67–86. [PubMed]
  • Collier RH, Kohlhaw G. Nonidentity of the aspartate and the aromatic aminotransferase components of transaminase A in Escherichia coli. J Bacteriol. 1972 Oct;112(1):365–371. [PMC free article] [PubMed]
  • Cosloy SD, Oishi M. Genetic transformation in Escherichia coli K12. Proc Natl Acad Sci U S A. 1973 Jan;70(1):84–87. [PubMed]
  • CURTIS SR., 3rd CHROMOSOMAL ABERRATIONS ASSOCIATED WITH MUTATIONS TO BACTERIOPHAGE RESISTANCE IN ESCHERICHIA COLI. J Bacteriol. 1965 Jan;89:28–40. [PMC free article] [PubMed]
  • Gelfand DH, Rudo N. Mapping of the aspartate and aromatic amino acid aminotransferase genes tyrB and aspC. J Bacteriol. 1977 Apr;130(1):441–444. [PMC free article] [PubMed]
  • Gibson F, Pittard J. Pathways of biosynthesis of aromatic amino acids and vitamins and their control in microorganisms. Bacteriol Rev. 1968 Dec;32(4 Pt 2):465–492. [PMC free article] [PubMed]
  • GROSS J, ENGLESBERG E. Determination of the order of mutational sites governing L-arabinose utilization in Escherichia coli B/r bv transduction with phage Plbt. Virology. 1959 Nov;9:314–331. [PubMed]
  • Helling RB. The effect of arabinose-specific enzyme synthesis on recombination in the arabinose genes of Escherichia coli. Genetics. 1967 Nov;57(3):665–675. [PubMed]
  • Im SW, Davidson H, Pittard J. Phenylalanine and tyrosine biosynthesis in Escherichia coli K-12: mutants derepressed for 3-deoxy-D-arabinoheptulosonic acid 7-phosphate synthetase (phe), 3-deoxy-D-arabinoheptulosonic acid 7-phosphate synthetase (tyr), chorismate mutase T-prephenate dehydrogenase, and transaminase A. J Bacteriol. 1971 Oct;108(1):400–409. [PMC free article] [PubMed]
  • Low KB. Escherichia coli K-12 F-prime factors, old and new. Bacteriol Rev. 1972 Dec;36(4):587–607. [PMC free article] [PubMed]
  • LOWRY OH, ROSEBROUGH NJ, FARR AL, RANDALL RJ. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed]
  • McGilvray D, Umbarger HE. Regulation of transaminase C synthesis in Escherichia coli: conditional leucine auxotrophy. J Bacteriol. 1974 Nov;120(2):715–723. [PMC free article] [PubMed]
  • Marcus M, Halpern YS. The metabolic pathway of glutamate in Escherichia coli K-12. Biochim Biophys Acta. 1969 Apr 1;177(2):314–320. [PubMed]
  • Mattern IE, Pittard J. Regulation of tyrosine biosynthesis in Escherichia coli K-12: isolation and characterization of operator mutants. J Bacteriol. 1971 Jul;107(1):8–15. [PMC free article] [PubMed]
  • Mavrides C, Orr W. Multispecific aspartate and aromatic amino acid aminotransferases in Escherichia coli. J Biol Chem. 1975 Jun 10;250(11):4128–4133. [PubMed]
  • RUDMAN D, MEISTER A. Transamination in Escherichia coli. J Biol Chem. 1953 Feb;200(2):591–604. [PubMed]
  • SILBERT DF, JORGENSEN SE, LIN EC. Repression of transaminase A by tyrosine in Escherichia coli. Biochim Biophys Acta. 1963 Jun 11;73:232–240. [PubMed]
  • Studier FW. The genetics and physiology of bacteriophage T7. Virology. 1969 Nov;39(3):562–574. [PubMed]
  • Taylor AL, Trotter CD. Linkage map of Escherichia coli strain K-12. Bacteriol Rev. 1972 Dec;36(4):504–524. [PMC free article] [PubMed]
  • VOGEL HJ, BONNER DM. Acetylornithinase of Escherichia coli: partial purification and some properties. J Biol Chem. 1956 Jan;218(1):97–106. [PubMed]
  • Wallace BJ, Pittard J. Regulator gene controlling enzymes concerned in tyrosine biosynthesis in Escherichia coli. J Bacteriol. 1969 Mar;97(3):1234–1241. [PMC free article] [PubMed]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)