Eukaryotic Mr 83,000 heat shock protein has a homologue in Escherichia coli.

We have isolated a gene from Escherichia coli homologous to the gene encoding the Mr 83,000 Drosophila heat shock protein (hsp83). In E. coli the protein homologous to hsp83 is a heat shock protein called C62.5. The predicted amino acid sequence of C62.5 is 41% and 42% identical to the Drosophila and human hsp83 proteins, respectively. Selected regions of the protein have conservation as high as 90%. The gene encoding C62.5 (named htpG) is located between the dnaZ and adk genes at 11.1 minutes on the E. coli chromosome. The htpG gene appears to be a newly identified locus. The isolation of an E. coli homologue of hsp83 illustrates the remarkable conservation of heat shock proteins in evolution and will facilitate genetic and biochemical experiments aimed at determining the function of hsp83.