The rpoD gene functions as a multicopy suppressor for mutations in the chaperones, CbpA, DnaJ and DnaK, in Escherichia coli.
The CbpA protein is an analog of the DnaJ molecular chaperone of Escherichia coli. The dnaJ- cbpA- double-null mutant exhibits severe defects in cell growth, namely, a very narrow temperature range for growth. To gain insight into the functions of CbpA as well as DnaJ, we isolated a multicopy suppressor gene that permits this dnaJ- cbpA- mutant to grow normally at low temperatures. The suppressor gene was identified as rpoD, the gene that encodes the major sigma 70. The biological implications of this finding are examined and discussed.
Shiozawa
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T
Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Japan.
Ueguchi
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C
Mizuno
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T
D001426:Bacterial Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005784:Gene Amplification; D005798:Genes, Bacterial; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D006360:Heat-Shock Proteins / Q000235:genetics; D018832:Molecular Chaperones / Q000235:genetics*; D009154:Mutation; D012808:Sigma Factor / Q000235:genetics; D013489:Suppression, Genetic
D001426:Bacterial Proteins; C085674:CbpA protein, E coli; D004268:DNA-Binding Proteins; C494635:DnaJ protein, E coli; D029968:Escherichia coli Proteins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D012808:Sigma Factor; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases; C063842:dnaK protein, E coli