Phylogenetic analysis of the third hsp70 homolog in Escherichia coli; a novel member of the Hsc66 subfamily and its possible co-chaperone

DNA Res. 1999 Oct 29;6(5):299-305. doi: 10.1093/dnares/6.5.299.


Novel members of the highly conserved protein family, Hsp70, have been found in the complete sequences of several genomes. To elucidate a phylogenetic relationship among Hsp70 proteins of Escherichia coli, we searched all open reading frames derived from 13 complete genomes for Hsp70/actin-related proteins by the single-linkage clustering method. Phylogenetic analysis of this superfamily revealed that E. coli possesses at least three Hsp70 homologs (DnaK, Hsc66 and Hsc62). We found that Hsc62, which is the product of hscC, is a new member of the Hsc66 subfamily, and is specific to E. coli. The analysis also suggested that YegD of E. coli is closely related to the actin family, which consists of the actin, FtsA and MreB subfamilies. A further database search revealed that two dnaJ homologs, ybeS and ybeV, were located on the opposite strand near hscC. Consequently, E. coli seems to have three gene clusters composed of DnaK and DnaJ homologs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / genetics
  • Amino Acid Sequence
  • Escherichia coli / chemistry
  • Escherichia coli / genetics*
  • Escherichia coli Proteins*
  • HSP40 Heat-Shock Proteins
  • HSP70 Heat-Shock Proteins / chemistry
  • HSP70 Heat-Shock Proteins / genetics*
  • Heat-Shock Proteins / chemistry
  • Heat-Shock Proteins / genetics
  • Molecular Sequence Data
  • Phylogeny
  • Sequence Alignment
  • Sequence Homology, Amino Acid


  • Actins
  • DnaJ protein, E coli
  • Escherichia coli Proteins
  • HSP40 Heat-Shock Proteins
  • HSP70 Heat-Shock Proteins
  • Heat-Shock Proteins
  • hscA protein, E coli
  • hscC protein, E coli
  • dnaK protein, E coli