Legionella pneumophila has two 60-kilodalton heat-shock proteins.
Legionella pneumophila is a thermotolerant bacterium. To learn more about the thermal adaptation of this organism, we studied the properties of the Legionella 60-kDa heat-shock protein (MopA, GroEL-analog, HtpB, Lp-Hsp60) in L. pneumophila and in an Escherichia coli strain containing the cloned gene. Lp-Hsp60 was found in both cytosol and membrane fractions; however, Lp-Hsp60 in the membrane fraction of L. pneumophila was slightly larger than Lp-Hsp60 in the cytosol. In contrast, both membrane-associated and cytosolic Lp-Hsp60 in the E. coli clone were similar in size to the smaller cytosolic Lp-Hsp60 of L. pneumophila. While peptide mapping suggests there are differences between the two proteins, the larger membrane-associated Lp-Hsp60 and the smaller cytosolic LP-Hsp60 shared Legionella-specific and E. coli GroEL cross-reacting epitopes, and the sequence of their first 20 N-terminal amino acids was identical. Further, Southern blot analysis of EcoRI-digested chromosomal DNA from several strains of L. pneumophila showed two fragments reacting with an htpAB-operon probe. In summary, L. pneumophila contains two Hsp60 proteins, and possibly two hsp60 genes.
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Research Service, 151, Dorn Veterans Hospital, Columbia, SC, USA.
Brown
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D000907:Antibodies, Bacterial; D002462:Cell Membrane / Q000737:chemistry; D018834:Chaperonin 60 / Q000032:analysis* / Q000737:chemistry* / Q000235:genetics; D003429:Cross Reactions; D003600:Cytosol / Q000737:chemistry; D004269:DNA, Bacterial / Q000032:analysis; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D016952:Legionella pneumophila / Q000737:chemistry* / Q000276:immunology; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis
D000907:Antibodies, Bacterial; D018834:Chaperonin 60; D004269:DNA, Bacterial; D010455:Peptides