Proteins of the Inner Membrane of Escherichia coli: Identification of Succinate Dehydrogenase by Polyacrylamide Gel Electrophoresis with sdh Amber Mutants

AUTOR(ES)

Spencer, Margaret E.

RESUMO

The inner or cytoplasmic membrane fraction of the cell envelope of Escherichia coli was isolated by isopycnic centrifugation on sucrose gradients. The membrane proteins were analyzed by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels (8.5%), and up to 56 bands were resolved. Different preparations gave very similar patterns of proteins. Succinate dehydrogenase mutants (sdh) were isolated which could not grow on succinate minimal medium, although growth on fumarate was unimpaired. The protein patterns of inner membrane preparations from sdh amber mutants were compared with the wild type, and one major band was greatly reduced in the mutants. This component, which represented approximately 5% of the inner membrane protein, was restored by introducing an amber suppressor gene (supU), which also restored the Sdh+ phenotype. The band corresponded to a protein with a molecular weight of 67,000 daltons, which is close to that for the large subunits of the succinate dehydrogenases of Rhodospirillum rubrum and beef heart mitochondria.

Documentos Relacionados

• Proteins of the Inner Membrane of Escherichia coli: Changes in Composition Associated with Anaerobic Growth and Fumarate Reductase Amber Mutation
• Two-Dimensional Polyacrylamide Gel Electrophoresis of Envelope Proteins of Escherichia coli
• Identification of Campylobacter jejuni and C. coli by gel electrophoresis of the outer membrane proteins.
• Identification of Mycoplasma and Other Microorganisms by Polyacrylamide-Gel Electrophoresis of Cell Proteins
• Identification of L Forms by Polyacrylamide-Gel Electrophoresis