From OMPwiki
Jump to: navigation, search

Cole, ST and Guest, JR (1979) Production of a soluble form of fumarate reductase by multiple gene duplication in Escherichia coli K12.Eur. J. Biochem. 102:65-71


1. Ampicillin-hyperresistant mutants of Escherichia coli K12 bearing multiple gene duplications in the ampC (beta-lactamase) gene region of the chromosome overproduced at least six proteins with molecular weights 97,000, 80,000, 72,000, 49,000, 33,000 and 26,500 during anaerobic growth. All but two of the proteins (80,000-Mr and 49,000-Mr) were also overproduced during aerobic growth. The distribution of the proteins in soluble and particulate cell fractions was investigated. 2. The 33,000-Mr and 72,000-Mr components were identified as beta-lactamase and the amp-linked frdA gene product, fumarate reductase, respectively. Co-sedimentation of the 26,500-Mr component with the fumarate reductase suggested that the smaller protein could be functionally related to the reductase. The lack of correspondence between the amplified proteins and the products of other amp-linked genes, aspA and mop(groE), indicated that these genes are not included in the repetitive sequence. 3. Fumarate reductase activities were amplified up to 32-fold by the multiple gene duplications. Two forms of fumarate reductase were produced: particulate (membrane-bound) and soluble (cytoplasmic). Production of the soluble form occurred when the binding capacity of the membrane was saturated. Both forms of fumarate reductase were enzymically active but the soluble form was readily inactivated under assay conditions.




Centrifugation, Density Gradient; Chromosome Aberrations; Electrophoresis, Polyacrylamide Gel; Escherichia coli; Fumarates; Molecular Weight; Mutation; Oxidoreductases; Solubility; Subcellular Fractions; beta-Lactamases

Main Points of the Paper

Please summarize the main points of the paper.

Materials and Methods Used

Please list the materials and methods used in this paper (strains, plasmids, antibodies, etc).

Phenotype Annotations

See Help:AnnotationTable for details on how to edit this table.

Phenotype of Taxon Information Genotype Information (if known) Condition Information OMP ID OMP Term Name ECO ID ECO Term Name Notes Status

a mutation or genetic difference within a strain

  • Taxon: Escherichia coli
  • Strain: K12
  • Substrain: JRG997
  • NCBI Taxon ID: 83333
  • Genotype of Reference Strain: ampC +
  • Genotype of Experimental Strain : ampC -
  • Reference Condition: anaerobic and aerobic growth medium
  • Experimental Condition: anaerobic and aerobic growth medium

increased gene expression


protein expression level analysis

a mutation or genetic difference within a strain

  • Taxon: Escherichia coli
  • Strain: K-12
  • Substrain:
  • NCBI Taxon ID: 83333
  • Genotype of Reference Strain: ampA
  • Genotype of Experimental Strain : ampA1
  • Reference Condition:

increased resistance to antimicrobial compound


traceable author statement

ampicillin resistance. Traceable here [1] [2]



See Help:References for how to manage references in OMPwiki.

  1. Normark, S & Burman, LG (1977) Resistance of Escherichia coli to penicillins: fine-structure mapping and dominance of chromosomal beta-lactamase mutations. J. Bacteriol. 132 1-7 PubMed OMPwiki page
  2. Held, WA & Smith, OH (1970) Mechanism of 3-methylanthranilic acid derepression of the tryptophan operon in Escherichia coli. J. Bacteriol. 101 209-17 PubMed OMPwiki page