title: lon gene product of Escherichia coli is a heat-shock protein.
abstract: The product of the pleiotropic gene lon is a protein with protease activity and has been tentatively identified as protein H94.0 on the reference two-dimensional gel of Escherichia coli proteins. Purified Lon protease migrated with the prominent cellular protein H94.0 in E. coli K-12 strains. Peptide map patterns of Lon protease and H94.0 were identical. A mutant form of the protease had altered mobility during gel electrophoresis. An E. coli B/r strain that is known to be defective in Lon function contained no detectable H94.0 protein under normal growth conditions. Upon a shift to 42 degrees C, however, the Lon protease was induced to high levels in K-12 strains and a small amount of protein became detectable at the H94.0 location in strain B/r. Heat induction of Lon protease was dependent on the normal allele of the regulatory gene, htpR, establishing lon as a member of the high-temperature-production regulon of E. coli.
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D005796:Genes; D005798:Genes, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000302:isolation & purification; D010446:Peptide Fragments / Q000032:analysis; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D010446:Peptide Fragments