The cbpA chaperone gene function compensates for dnaJ in lambda plasmid replication during amino acid starvation of Escherichia coli.
We found previously that lambda plasmid DNA replication in amino acid-starved Escherichia coli relA mutants (i.e., during the relaxed response), which is carried out by the inherited replication complex, is dependent on functions of DnaK and GrpE molecular chaperones but proceeds in a dnaj mutant at a nonpermissive temperature. Here we demonstrate that this replication is inhibited when functions of both dnaJ and cbpA are impaired. In complete media, the growth of the lambda pi A66 phage (capable of replicating in E. coli dnaJ, dnaK, and grpE missense mutants at 30 degrees C), as well as efficiency of transformation by the lambda pi A66 plasmid, is significantly decreased in a dnaJ259 cbpA::kan double mutant. These results strengthen the proposal of other authors (C. Ueguchi, M. Kakeda, H. Yamada, and T. Mizuno, Proc. Natl. Acad. Sci. USA 91:1054-1058, 1994; C. Ueguchi, T. Shiozawa, M. Kakeda, H. Yamada, and T. Mizuno, J. Bacteriol. 177:3894-3896, 1995; and T. Yamashino, M. Kakeda, C. Ueguchi, and T. Mizuno, Mol. Microbiol. 13:475-483, 1994) that the cbpA gene product is a functional analog of the DnaJ chaperone in E. coli.
Wegrzyn
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Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Laboratory of Molecular Biology affiliated to the University of Gdańsk, Poland. wegrzyn@biotech.univ.gda.pl
Taylor
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Wegrzyn
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D000596:Amino Acids / Q000172:deficiency*; D010582:Bacteriophage lambda / Q000235:genetics / Q000254:growth & development; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000821:virology; D029968:Escherichia coli Proteins; D050956:HSP40 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D014169:Transformation, Bacterial; D010948:Viral Plaque Assay
D000596:Amino Acids; C085674:CbpA protein, E coli; D004279:DNA, Viral; D004268:DNA-Binding Proteins; C494635:DnaJ protein, E coli; D029968:Escherichia coli Proteins; D050956:HSP40 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones