1887

Abstract

SUMMARY: Serine acetyltransferase (SAT) from is subject to feedback inhibition by -cysteine. A mutant was isolated which excretes -cysteine because of a lesion in , the structural gene for SAT, rendering the enzyme less feedback sensitive. To analyse the structural basis for this mutation the genes both from wild-type and the mutant strain were cloned and their nucleotide sequences determined. The gene contained an open reading frame consisting of 819 bp, equivalent to a protein of 273 amino acids. The mutant gene showed a single base change in position 767 resulting in a methionine to isoleucine substitution. A causal connection between this SAT sequence alteration, feedback insensitivity and -cysteine excretion was demonstrated. The SAT from the wild-type strain was purified. It was composed of a single polypeptide chain migrating in SDS gels according to an of 34000. As in , the enzyme was associated in a bifunctional complex with -acetylserine (thiol)-lyase.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-133-3-515
1987-03-01
2024-04-24
Loading full text...

Full text loading...

/deliver/fulltext/micro/133/3/mic-133-3-515.html?itemId=/content/journal/micro/10.1099/00221287-133-3-515&mimeType=html&fmt=ahah

References

  1. Bolivar F., Rodriguez R. L., Greene P. J., Betlach M. C., Heynecker H. L., Boyer H. W., Crosa J. H., Falkow S. 1977; Construction and characterization of new cloning vehicles. II. A multipurpose cloning system. Gene 2:95–113
    [Google Scholar]
  2. Christen A. A., Pall M. L., Manzara T., Lurquin P. F. 1983; Rapid isolation of Escherichia coli minicells by glass-fiber filtration: study of plasmid-coded polypeptides. Gene 23:195–198
    [Google Scholar]
  3. Dougan G., Sherrat D. 1977; The transposon TN7 as a probe for studying Col El structure and function. Molecular and General Genetics 151:151–160
    [Google Scholar]
  4. Gaitonde M. K. 1967; A spectrophotometric method for the direct determination of cysteine in the presence of other naturally occurring amino acids. Biochemical Journal 104:627–633
    [Google Scholar]
  5. Goldberg R. B., Bender R. A., Streicher S. L. 1974; Direct selection for PI sensitive mutants of enteritic bacteria. Journal of Bacteriology 118:810–814
    [Google Scholar]
  6. Gray C. P., Sommer R., Polke C., Beck E., Schaller H. 1978; Structure of the orgin of DNA replication of bacteriophage fd. Proceedings of the National Academy of Science of the United States of America 75:50–53
    [Google Scholar]
  7. Hentschel C., Irminger J. C., Buchner P., Birnstiel M. L. 1980; Sea urchin histone mRNA termini are located in gene regions downstream from putative regulatory sequences. Nature; London: 285147–151
    [Google Scholar]
  8. Jones-Mortimer M. C. 1968; Positive control of sulphate reduction in Escherichia coli: isolation, characterization and mapping of cysteineless mutants of E. coli K12. Biochemical Journal 110:589–595
    [Google Scholar]
  9. Jones-Mortimer M. C., Wheldrake I. F., Pasternak C. A. 1968; The control of sulphate reduction in Escherichia coli by O-acetyl-l-serine. Biochemical Journal 107:51–53
    [Google Scholar]
  10. Krauss K. F. 1984; Funktion, Eigenschaften und Regulation der multifunktionalen Cysteinsynthase und einiger am Cysteinstoffwechsel beteiligter Enzyme beim Wachstum von Chlorella fusca auf verschiedenen schwefelhaltigen Verbindungen. Dissertation, Ludwig-Maximilians-Universität München.:
    [Google Scholar]
  11. Kredich N. M. 1971; Regulation of cysteine biosynthesis in Salmonella typhimurium I. Effects of growth on varying sulfur sources and O-acetyl-l-serine on gene expression. Journal of Biological Chemistry 246:3474–3484
    [Google Scholar]
  12. Kredich N. M. 1983; Regulation of cysteine biosynthesis in Escherichia coli and Salmonella typhimurium. In Amino Acids: Biosynthesis and Genetic Regulation pp. 115–132 Herrmann K. M., Somerville R. L. Edited by Mass: Addison-Wesley;
    [Google Scholar]
  13. Kredich N. M., Tomkins G. 1966; The enzymatic synthesis of l-cysteine in Escherichia coliand Salmonella typhimurium. Journal of Biological Chemistry 241:4955–4965
    [Google Scholar]
  14. Kredich N. M., Becker M. A., Tomkins G. M. 1969; Purification and characterization of cysteine synthase, a bifunctional protein complex from Salmonella typhimurium. Journal of Biological Chemistry 244:2428–2439
    [Google Scholar]
  15. Laemmli U. K. 1970; Cleavage of structural proteins during the assembly of the head of the bacteriophage T4. Nature; London: 227680–685
    [Google Scholar]
  16. Maloy S. R., Nunn W. D. 1981; Selection for loss of tetracycline resistance by Escherichia coli. Journal of Bacteriology 145:1100–1112
    [Google Scholar]
  17. Maniatis T., Fritsch E. R., Sambrook J. 1982 Molecular Cloning Cold Spring Harbor, NY:: Cold Spring Harbor Laboratory.;
    [Google Scholar]
  18. Maxam A. M., Gilbert W. 1980; Sequencing end- labelled DNA with base-specific chemical cleavages. Methods in Enzymology 65:499–560
    [Google Scholar]
  19. Miller J. H. 1972 Experiments in Molecular Genetics Cold Spring Harbor, NY:: Cold Spring Harbor Laboratory.;
    [Google Scholar]
  20. Neidhardt F. C., Bloch P. L., Smith D. F. 1974; Culture medium for enterobacteria. Journal of Bacteriology 119:736–747
    [Google Scholar]
  21. Saito H., Miura K. J. 1963; Preparation of transforming deoxyribonucleic acid by phenol treatment. Biochimica et biophysica acta 72:619–629
    [Google Scholar]
  22. Wich G., Hummel H., Jarsch M., BÄr U, BÖck A. 1986; Transcription signals for stable RNA genes in Methanococcus. Nucleic Acids Research 14:2459–2479
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-133-3-515
Loading
/content/journal/micro/10.1099/00221287-133-3-515
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error